Rust visual glitch, screen split into 4 quadrants, Mac

I tried playing Rust again after a while and upon joining the server my screen looked like this (see image below). My screen is split into 4 quadrants 3 of them are blue and washed, they look like water and sky and the other one looks like regular rust but water and sky look weird. I think there is a problem with the game when it tries to render the final image. Instead of putting blue “filter” where water and sky are it puts it all over 3/4 of the screen. I tried reinstalling and changing every graphic and video setting but nothing helped. I contacted Rust support and also reported it in game but got no success that way. Rust support would just ignore my messages or insist that there is something wrong with my computer, even tho everything else works fine. So I am hoping I will find some help here. Please let me know if you have any suggestions or advice. I am using a Mac computer, more specific late 2014 iMac 5k with 4th gen i5 and R9 M290x 2GB.

Thanks in advance!

This is a screenshot of what my game looks like. You can see both sky and water and other terrain and how they are rendered on both parts of the screen.