rx480 graphical issues in-game

[XATEV]

Hello there!

First of all I'm glad to finally have joined the LTT forums after several years. Thanks for having me here 
Ever since I bought a new GPU few months ago, more specifically an rx480, I've had issues with games running on OpenGl. Even on a fresh Ubuntu (18.04LTS) install, which as far as I am concerned comes with open source amdgpu drivers will cause severe graphical issues in-game. Other games, for example ones that run on DirectX, have caused no issues whatsoever. From my understanding OpenGl support on Windows is rather not satisfactory, on the other hand Linux and its existing open source amd drivers are supposed to provide good support. 

I'm not sure where to proceed at this point, searching for this issue has provided no solution so far which is why I'm hoping to find some opinions on this matter here. The attachment contains one example which showcases the issue I'm having on both Linux & Windows.