Changes to "Home" page are not saved

Hello Community,
lately I have been having issues with editing my “home” page which has not been a problem before. I have updated to the newest WP version 4.8 and tried deactivating all plugins that are active.

The problem I have is that my changes that I add to the home page are not saved, bur rather deleted. This applies to the front- and the back end. Let me make an example. I go to the home page and want add one “color section” with 3x 1/3 boxes. Here I want to showcase my services. After finishing the elements with text and a large icon box I go to save. What happens next is that my changes are deleted. They are not visible in the back end nor in the front end anymore.

I have opened a post already that has been closed unfortunately without resolving the issue. I already tried to newly install the enfold theme via the ftp but unfortunately could not figure out the problem. Funny is that this problem only seems to occur on the “home” page.

Hope you can help out :)

Best and thanks,

Simon