Page Builder: editor is empty, page (luckily) shows all content

Hi there! I love your page builder plugin. For some reason, I currently have trouble editing one particular page (which happens to be the front page of my homepage). When I open the editor there is no entry at all and it says that the page was last updated in October (it was last updated end of November). When I open the page the content is there and up to date. I had similar problems before with other pages but normally it would work after restarting my browser. Now nothing works: Changing the front page, checking for conflicts with other plugins… I’m using the current Word Press version 4.6.1 with the theme Spacious Pro (version 2.0.8). Does anyone have an idea how to fix that? Thanks!