Major graphic issues on Mac

Hi everyone!

Recently I got back into the Sims 3 and had to move from Origin to the EA app. Ever since switching I've been having graphical issues that make the game unplayable. I am able to enter a save but during loading (about halfway) the game starts looking like in the screenshot. The screen also flashes a lot. I decided to uninstall all custom and store content as well as mods. I also tried playing on base graphical settings and in a window but nothing works. Like I said, when I was playing the Sims through Origin on the same computer, it ran smoothly on more advanced settings in full screen mode with a lot of CC. It's only after switching to the EA app that the problems started.