The fpsVR developer also implemented the fix:
"Explanation of issue:
Windows 11 multimedia timer resolution for any process depends on the state of its window. Higher resolution can improve the accuracy of time-out intervals in wait functions, which is very important for the VR frame generation pipeline. Starting with Windows 11, by default if a window-owning process becomes fully occluded, minimized, or otherwise invisible or inaudible to the end user, Windows may automatically ignore the timer resolution request and thus does not guarantee a higher resolution than the default system resolution."
I haven't tested if the fix, but here is from the FpsVR developer too:
How does fpsVR solve this issue in 1.23 update?
On startup, fpsVR launches the w11fix.exe file (added in this update). This file changes the properties of the SteamVR and Oculus processes, it explicitly disabling the PROCESS_POWER_THROTTLING_IGNORE_TIMER_RESOLUTION property.
This fix is separated into a separate file for the following reasons:
1) This fix uses a new Windows API for Windows 11
2) If you are using Oculus headsets, you can run this file before starting a game session, even for games from the Oculus store, so as no need to start SteamVR and fpsVR. The file is located in the fpsVR root folder.
3) You can freely share this file with anyone who does not use fpsVR.
Warning: w11fix.exe is small, only 15 kilobytes, it is possible that some antiviruses will falsely detect something, if this happens, just add it to your antivirus exclusions.