Cant save in divi when rankmath is enabled

Hi
I have stumbled upon a problem on one of the sites I administrate. When activating rankmath i get a error message when trying to save with divi. I have tried to increase max vars, php memory, disable all other plugins. Removed the js codes in header but with no luck. I have searched on forums and on the web for a solution but i cant find a working solution.

I have tried trouble shooting mode, and with rankmath as the only plugin activated all works as it should, but with divi theme it wont work.

I have other clients with divi and rankmath that works as it should so i cant see why it wont work for this site.

I have created a temporary dev server, whit the site that gives problem and attached in sensitive data a temporary login link.

“Help me, Rank-Math Kenobi. You’re my only hope”