Cannot save widgets in block mode after last updates

Hi there, I cannot save any widget in my widget areas after the last updates. WordPress tells the answer is not a valid JSON and in console I get 403/400 error depending on the hosting setup. I did check if the request to /wp-json/batch/v1?_locale=user is legit, and it verified as correct json, so the only possible outcome from my testing is that the hosting provider are marking the request as a threat in their waf rule set. This is happening with 3 providers for now: aruba, v-hosting and namecheap. I am reaching out to them to try get their waf logs.

sopb 2.35.0
widgets 1.74.2
wp latest and other plugins up to date

Below an example anonymized failed request

{
  "validation": "require-all-validate",
  "requests": [
    {
      "path": "/wp/v2/widgets/block-2",
      "body": {
        "id": "block-2",
        "instance": {
          "raw": {
            "content": "<!-- wp:siteorigin-panels/layout-block {"panelsData":{"widgets":[{"image":7530,"image_fallback":"","size":"thumbnail","size_width":"","size_height":"","size_external":"custom_size","size_external_width":"","size_external_height":"","align":"left","title_align":"default","title":"","title_position":"hidden","alt":"","url":"","bound":true,"rel":"","image_shape":{"shape":"","repeat":"no-repeat","size":"","alignment":"center","so_field_container_state":"open","enable":""},"_sow_form_id":"131764073969eb2bdec7e8a114863243","_sow_form_timestamp":1785490198496,"link_title":"","new_window":"","full_width":"","panels_info":{"class":"SiteOrigin_Widget_Image_Widget","grid":0,"cell":0,"id":0,"widget_id":"a07312fd-0aca-4d69-b563-d3104c2a06f2","style":{"background_image_attachment":false,"background_display":"tile","background_image_size":"full","background_image_opacity":"100","border_thickness":"1px","gsap_widget_entrance":"disabled"}}},{"title":"Seguici sui nostri social","nav_menu":10,"panels_info":{"class":"WP_Nav_Menu_Widget","grid":0,"cell":1,"id":1,"widget_id":"b8145935-ec05-4695-8061-a66bbf40d4ba","style":{"class":"text-right","background_image_attachment":false,"background_display":"tile","background_image_size":"full","background_image_opacity":"100","border_thickness":"1px","gsap_widget_entrance":"disabled"}}},{"title":"","text":"\u003cp\u003eVia delle Prove, 1 – Città 00000\u003cbr /\u003e\n(di fronte alla stazione centrale)\u003cbr /\u003e\nzona Centro – I Municipio\u003c/p\u003e\n","text_selected_editor":"tinymce","autop":true,"_sow_form_id":"18739078936a6c6b12a100f297430214","_sow_form_timestamp":1785490198503,"panels_info":{"class":"SiteOrigin_Widget_Editor_Widget","grid":1,"cell":0,"id":2,"widget_id":"2a196666-4625-44ea-8e48-59735c87c41e","style":{"background_image_attachment":false,"background_display":"tile","background_image_size":"full","background_image_opacity":"100","border_thickness":"1px","gsap_widget_entrance":"disabled"}}},{"nav_menu":11,"panels_info":{"class":"WP_Nav_Menu_Widget","grid":1,"cell":1,"id":3,"widget_id":"cb12334e-9a79-4d97-9939-ad24f0b9e6cb","style":{"background_image_attachment":false,"background_display":"tile","background_image_size":"full","background_image_opacity":"100","border_thickness":"1px","gsap_widget_entrance":"disabled"}}},{"nav_menu":12,"panels_info":{"class":"WP_Nav_Menu_Widget","grid":1,"cell":2,"id":4,"widget_id":"cacfef3b-ba80-4334-b057-3f385889936b","style":{"background_image_attachment":false,"background_display":"tile","background_image_size":"full","background_image_opacity":"100","border_thickness":"1px","gsap_widget_entrance":"disabled"}}},{"nav_menu":13,"panels_info":{"class":"WP_Nav_Menu_Widget","grid":1,"cell":3,"id":5,"widget_id":"0035808d-d1d4-4c82-9ea0-10e43b0325ec","style":{"background_image_attachment":false,"background_display":"tile","background_image_size":"full","background_image_opacity":"100","border_thickness":"1px","gsap_widget_entrance":"disabled"}}},{"nav_menu":14,"panels_info":{"class":"WP_Nav_Menu_Widget","grid":1,"cell":4,"id":6,"widget_id":"422fcc1a-b122-4071-b998-820a411f4c53","style":{"background_image_attachment":false,"background_display":"tile","background_image_size":"full","background_image_opacity":"100","border_thickness":"1px","gsap_widget_entrance":"disabled"}}},{"nav_menu":15,"panels_info":{"class":"WP_Nav_Menu_Widget","grid":1,"cell":5,"id":7,"widget_id":"0f96583e-98a7-4a9d-a488-a5620ec5a5fb","style":{"background_image_attachment":false,"background_display":"tile","background_image_size":"full","background_image_opacity":"100","border_thickness":"1px","gsap_widget_entrance":"disabled"}}}],"grids":[{"cells":3,"style":{"class":"border__top","background":"#008894","background_image_attachment":false,"background_display":"tile","background_image_size":"full","background_image_opacity":"100","border_thickness":"1px","full_height":"","row_stretch":"full","cell_alignment":"flex-start","s2s_row":""}},{"cells":6,"style":{"class":"border__bottom","background":"#008894","background_image_attachment":false,"background_display":"tile","background_image_size":"full","background_image_opacity":"100","border_thickness":"1px","full_height":"","row_stretch":"full","cell_alignment":"flex-start","s2s_row":""}}],"grid_cells":[{"grid":0,"index":0,"weight":0.6411347517730497,"style":[]},{"grid":0,"index":1,"weight":0.31962813877707497,"style":[]},{"grid":0,"index":2,"weight":0.03923710944987537,"style":[]},{"grid":1,"index":0,"weight":0.25,"style":[]},{"grid":1,"index":1,"weight":0.15,"style":[]},{"grid":1,"index":2,"weight":0.15,"style":[]},{"grid":1,"index":3,"weight":0.15,"style":[]},{"grid":1,"index":4,"weight":0.15,"style":[]},{"grid":1,"index":5,"weight":0.15,"style":[]}]},"contentPreview":"\u003cdiv id=\u0022pl-\u0022  class=\u0022panel-layout\u0022 \u003e\u003cdiv id=\u0022pg\u002d\u002d0\u0022  class=\u0022panel-grid panel-has-style has-bg-color cell-flex-start\u0022 \u003e\u003cdiv class=\u0022border__top siteorigin-panels-stretch panel-row-style panel-row-style-for\u002d\u002d0\u0022 data-stretch-type=\u0022full\u0022 \u003e\u003cdiv class=\u0022so-panels-full-wrapper\u0022 \u003e\u003cdiv id=\u0022pgc\u002d\u002d0-0\u0022  class=\u0022panel-grid-cell\u0022 \u003e\u003cdiv id=\u0022panel\u002d\u002d0-0-0\u0022 class=\u0022so-panel widget widget_sow-image panel-first-child panel-last-child\u0022 data-index=\u00220\u0022 \u003e\u003cdiv\n\t\t\t\n\t\t\tclass=\u0022so-widget-sow-image so-widget-panels-preview\u0022\n\t\t\t\n\t\t\u003e\n\u003cdiv class=\u0022sow-image-container\u0022\u003e\n\t\t\u003cimg \n\tsrc=\u0022https://www.example-site.test/wp-content/uploads/2026/01/sample-logo-image-150x150.png\u0022 width=\u0022150\u0022 height=\u0022150\u0022 srcset=\u0022https://www.example-site.test/wp-content/uploads/2026/01/sample-logo-image-150x150.png 150w, https://www.example-site.test/wp-content/uploads/2026/01/sample-logo-image-300x300.png 300w, https://www.example-site.test/wp-content/uploads/2026/01/sample-logo-image.png 360w\u0022 sizes=\u0022(max-width: 150px) 100vw, 150px\u0022 alt=\u0022\u0022 decoding=\u0022async\u0022 loading=\u0022lazy\u0022 \t\tclass=\u0022so-widget-image\u0022/\u003e\n\t\u003c/div\u003e\n\n\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\u0022pgc\u002d\u002d0-1\u0022  class=\u0022panel-grid-cell panel-grid-cell-mobile-last\u0022 \u003e\u003cdiv id=\u0022panel\u002d\u002d0-1-0\u0022 class=\u0022so-panel widget widget_nav_menu panel-first-child panel-last-child\u0022 data-index=\u00221\u0022 \u003e\u003cdiv class=\u0022text-right panel-widget-style panel-widget-style-for\u002d\u002d0-1-0\u0022 \u003e\u003ch3 class=\u0022widget-title\u0022\u003eSeguici sui nostri social\u003c/h3\u003e\u003cdiv class=\u0022menu-social-container\u0022\u003e\u003cul id=\u0022menu-social\u0022 class=\u0022menu\u0022\u003e\u003cli id=\u0022menu-item-6948\u0022 class=\u0022social-item menu-item menu-item-type-custom menu-item-object-custom menu-item-6948\u0022\u003e\u003ca href=\u0022https://www.facebook.com/exampleorg/\u0022\u003eFacebook\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-6949\u0022 class=\u0022social-item menu-item menu-item-type-custom menu-item-object-custom menu-item-6949\u0022\u003e\u003ca href=\u0022https://www.instagram.com/exampleorg/\u0022\u003eInstagram\u003c/a\u003e\u003c/li\u003e\n\u003c/ul\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\u0022pgc\u002d\u002d0-2\u0022  class=\u0022panel-grid-cell panel-grid-cell-empty\u0022 \u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\u0022pg\u002d\u002d1\u0022  class=\u0022panel-grid panel-has-style has-bg-color cell-flex-start\u0022 \u003e\u003cdiv class=\u0022border__bottom siteorigin-panels-stretch panel-row-style panel-row-style-for\u002d\u002d1\u0022 data-stretch-type=\u0022full\u0022 \u003e\u003cdiv class=\u0022so-panels-full-wrapper\u0022 \u003e\u003cdiv id=\u0022pgc\u002d\u002d1-0\u0022  class=\u0022panel-grid-cell\u0022 \u003e\u003cdiv id=\u0022panel\u002d\u002d1-0-0\u0022 class=\u0022so-panel widget widget_sow-editor panel-first-child panel-last-child\u0022 data-index=\u00222\u0022 \u003e\u003cdiv\n\t\t\t\n\t\t\tclass=\u0022so-widget-sow-editor so-widget-panels-preview\u0022\n\t\t\t\n\t\t\u003e\n\u003cdiv class=\u0022siteorigin-widget-tinymce textwidget\u0022\u003e\n\t\u003cp\u003eVia delle Prove, 1 – Città 00000\u003cbr /\u003e\n(di fronte alla stazione centrale)\u003cbr /\u003e\nzona Centro – I Municipio\u003c/p\u003e\n\u003c/div\u003e\n\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\u0022pgc\u002d\u002d1-1\u0022  class=\u0022panel-grid-cell\u0022 \u003e\u003cdiv id=\u0022panel\u002d\u002d1-1-0\u0022 class=\u0022so-panel widget widget_nav_menu panel-first-child panel-last-child\u0022 data-index=\u00223\u0022 \u003e\u003cdiv class=\u0022menu-teatro-container\u0022\u003e\u003cul id=\u0022menu-teatro\u0022 class=\u0022menu\u0022\u003e\u003cli id=\u0022menu-item-6950\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6950\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-26/\u0022\u003eVoce menu 26\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-6952\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6952\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-22/\u0022\u003eVoce menu 22\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-6953\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6953\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-18/\u0022\u003eVoce menu 18\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-6951\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6951\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-17/\u0022\u003eVoce menu 17\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-6954\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6954\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-16/\u0022\u003eVoce menu 16\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-40704\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-40704\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-24/\u0022\u003eVoce menu 24\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-6955\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6955\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-19/\u0022\u003eVoce menu 19\u003c/a\u003e\u003c/li\u003e\n\u003c/ul\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\u0022pgc\u002d\u002d1-2\u0022  class=\u0022panel-grid-cell\u0022 \u003e\u003cdiv id=\u0022panel\u002d\u002d1-2-0\u0022 class=\u0022so-panel widget widget_nav_menu panel-first-child panel-last-child\u0022 data-index=\u00224\u0022 \u003e\u003cdiv class=\u0022menu-famiglie-container\u0022\u003e\u003cul id=\u0022menu-famiglie\u0022 class=\u0022menu\u0022\u003e\u003cli id=\u0022menu-item-7532\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-7532\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-21/\u0022\u003eVoce menu 21\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-7534\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-7534\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-3/\u0022\u003eVoce menu 3\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-7533\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-7533\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-1/\u0022\u003eVoce menu 1\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-6958\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6958\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-10/\u0022\u003eVoce menu 10\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-40300\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-40300\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-8/\u0022\u003eVoce menu 8\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-6957\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6957\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-11/\u0022\u003eVoce menu 11\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-6960\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6960\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-14/\u0022\u003eVoce menu 14\u003c/a\u003e\u003c/li\u003e\n\u003c/ul\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\u0022pgc\u002d\u002d1-3\u0022  class=\u0022panel-grid-cell\u0022 \u003e\u003cdiv id=\u0022panel\u002d\u002d1-3-0\u0022 class=\u0022so-panel widget widget_nav_menu panel-first-child panel-last-child\u0022 data-index=\u00225\u0022 \u003e\u003cdiv class=\u0022menu-scuole-container\u0022\u003e\u003cul id=\u0022menu-scuole\u0022 class=\u0022menu\u0022\u003e\u003cli id=\u0022menu-item-6961\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6961\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-23/\u0022\u003eVoce menu 23\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-10231\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-10231\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-7/\u0022\u003eVoce menu 3\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-10232\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-10232\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-5/\u0022\u003eVoce menu 1\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-40139\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-40139\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-2/\u0022\u003eVoce menu 2\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-6962\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6962\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-4/\u0022\u003eVoce menu 4\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-6963\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6963\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-13/\u0022\u003eVoce menu 13\u003c/a\u003e\u003c/li\u003e\n\u003c/ul\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\u0022pgc\u002d\u002d1-4\u0022  class=\u0022panel-grid-cell\u0022 \u003e\u003cdiv id=\u0022panel\u002d\u002d1-4-0\u0022 class=\u0022so-panel widget widget_nav_menu panel-first-child panel-last-child\u0022 data-index=\u00226\u0022 \u003e\u003cdiv class=\u0022menu-organizzatori-container\u0022\u003e\u003cul id=\u0022menu-organizzatori\u0022 class=\u0022menu\u0022\u003e\u003cli id=\u0022menu-item-6968\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6968\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-25/\u0022\u003eVoce menu 25\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-6965\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6965\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-15/\u0022\u003eVoce menu 15\u003c/a\u003e\u003c/li\u003e\n\u003c/ul\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\u0022pgc\u002d\u002d1-5\u0022  class=\u0022panel-grid-cell\u0022 \u003e\u003cdiv id=\u0022panel\u002d\u002d1-5-0\u0022 class=\u0022so-panel widget widget_nav_menu panel-first-child panel-last-child\u0022 data-index=\u00227\u0022 \u003e\u003cdiv class=\u0022menu-progetti-speciali-container\u0022\u003e\u003cul id=\u0022menu-progetti-speciali\u0022 class=\u0022menu\u0022\u003e\u003cli id=\u0022menu-item-6969\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6969\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-20/\u0022\u003eVoce menu 20\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-6972\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6972\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-9/\u0022\u003eVoce menu 2\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-6970\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6970\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-6/\u0022\u003eVoce menu 6\u003c/a\u003e\u003c/li\u003e\n\u003cli id=\u0022menu-item-6971\u0022 class=\u0022menu-item menu-item-type-post_type menu-item-object-page menu-item-6971\u0022\u003e\u003ca href=\u0022https://www.example-site.test/pagina-12/\u0022\u003eVoce menu 12\u003c/a\u003e\u003c/li\u003e\n\u003c/ul\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"} /-->"
          }
        }
      },
      "method": "PUT"
    }
  ]
}