Home Page keeps resetting to earlier version, changes won't stick

Hi,

I have Enfold 4.5.5 installed on WordPress 5.1.1, and I keep having this one very frustrating problem: When I make changes to the home page, my changes won’t stay. I hit update, and then I can see my changes as long as I have the editor open, but as soon as I close the editor and view the page, all my changes are gone and the home page is reset to an earlier version. Weirdly though, this mistake seems to happen randomly: Sometimes, even after I close the editor, my changes are still there, and I think I might have solved the problem, but then next time, everything back to zero.

Solutions I’ve tried:

• duplicating the home page and using the new one
• increading memory limit to 256M
• validating the mark-up, I found a mistake, there was a closing </p> tag without an opening <p>, it was added by WordPress automatically, so I deactivated this function in functions.php. Then the mark-up validated, but problem persisted.
• disabling Gutenberg editor with a plugin
• deactivating all plugins, problems was still there with all plugins deactivated

I’d appreciate if you could look into this!
Thank you,
Tina