Pixelated Viewport after VR Preview

Hi, I am currently working on a VR Project where I received a quick&dirty project file and have encountered a problem when playing in VR Preview.

Before I click play everything looks fine but afterwards everything looks pixelated and quite unusual. I have to mention that in the current form the projects performance is far from ok (20fps) due to 0 optimizations. Could it be that due to the lack of fps the engine renders the frame only partly?

Before:

After:

Furthermore the whole projects is sequenced and includes a movie file. Could it be that UE prioritizes the framerate of the movie and does everything it can to accomodate the rest to that?

Thx in advance

Alright saw the previous post, it’s a bug with AMD Cards,:

Bug UE-64034: Unreal Engine Issues and Bug Tracker (UE-64034)

Downgraded to 4.19.2