Bug Planar Reflection Probe seems to use very low resolution in play mode / build

Hey, I am using Planar Reflection Probe as a mirror with a resolution of 2048, which seemed to be reasonable in terms of ratio between performance and quality in HDRP 7.5 (not looking great, but 4096 already was too slow).
In HDRP 10.4 now it looks fine in Editor, but as soon as I enter play mode, and also in final build, it looks like 8 Bit graphics from the past (really low resolution). I am using SteamVR, latest version, Deferred rendering, Unity 2020 LTS, HDRP 10.4.
Looks like either a bug or some settings which I am not able to find, but I assume the former, as it worked fine in 7.5 and it looks alright in scene view.

 

I basically tried all settings I could find; even started project from scratch, all same result: It seems that somehow in VR, planar reflection probes are now rendered with at most half resolution then what we set in the Editor. This was not happening in 7.x versions of HDRP.
This prevents us from already migrating to 10.4 / 2020 LTS, although everything else works quite well, and performance got a huge boost without any changes.

 

Hey @SebLagarde, thx for getting back! I can confirm it ONLY happens in VR mode. With VR, it's easy to reproduce. I can send in a relatively small test project (new HDRP standard scene with Planar Reflection Probe and SteamVR added), if this helps.

 

@SebLagarde would SteamVR project help? I could also try to replicate with OpenXR plugin, if this helps more.

 

Any opinions on this? Sorry to bother, but the current situation is really not good. If I double the resolution to 4096, it still looks worse then with 2048 on HDRP 7.5.1. With 2048 it looks like 8 Bit graphics from the past, it's really that bad.
It seems to depend on the resolution or FOV of headset somehow, as with e.g. Valve Index it is worse then with Quest. Also got some Unity crash after switching to 4096, due to some swapping issues as it seems.