Divi Single Builder for MEC causes conflicts

I finally figured out what’s causing my errors! It is the addon Divi Single Builder for MEC.

My plugins page in the dashboard has been very slow for a long time. In addition, I could not look at the changelogs for some plugins. I always got the error message: Plugin not found. But the plugins were there and I was also able to update them. In the console I could see that I got an internal server error in the plugins-install.php when I clicked on the changelogs.
So I gradually deactivated all plugins. Lo and behold, once Divi Single Builder for MEC is disabled, everything works fine.

The page I need help with: [log in to see the link]