Page updates failing

Firstly, love SiteOrigin. I had paid for a different site builder plugin a while back and cancelled it because the free version of Page Builder had so much more.

I’ve recently started hitting a problem that I’ve never seen before, though. I have my home page set up with Page Builder (template = Page Builder Home). Anytime I click “Update” on this page, instead of refreshing the Edit Page screen as per usual, it goes to /wp-admin/post.php and essentially ends up in a Page Not Found error.

I can’t explain this as last week it worked perfectly fine. I haven’t added any new plugins. Any thoughts on what’s going on here…is this potentially with my host or wordpress instance?

Thanks in advance!