4.21 Performance Issues

When I create a VR game (Binary Ue4.21 from Epic Launcher) for the Oculus store which is using simple Cartoonish asset, the app will not run on 90hz. Even in empty levels. I optimized probably everything:

What I did:
Static lightsource
 Only Static lightning
enabled Forward shading
enabled Instanced Stereo
changed from TemporalAA to MSAA
enabled Adaptive Pixel Density
disabled main Post Process features (Bloom, Lensflare)
 disabled Composite Depth (caused z-fighting on AMD)
made no gameplay use of Event tick
Smooth FPS is off and min. desired frame rates by 90

Does anyone got an idea what I could do? Is it a bug?