Weird VR preview window in 4.21

Hi,

I have a strange issue with one of my projects. When doing a VR preview with an Oculus Rift, I get this preview screen:

I have no idea how this happened. And when I try to change the SpectatorScreenMode with vr.SpectatorScreenMode it has no effect.

Any ideas on how to fix this?

And then I remember this project started out as a Vive project in 4.12 using a older method that set a higher ScreenPercentage… problem solved!

I am having the same problem, but with a project that was ported from 4.19. However, I am not doing anything with ScreenPercentage. Could you explain in a bit more detail what you did to resolve it?
Thanks

EDIT: nvm, I found out that my PostProcessingVolume actually was setting the ScreenPercentage to a different value. Setting this back to default fixed it.