So i have asked about this problem on an another forum, and somebody told me when they switched from the Rift S to the oculus quest 2 they started to get the same problem.
I'm using the Oculus quest 2 with a link cable. The game i get this problem on is called DCS.
While playing DCS with minimal graphics settings I can get massive FPS drops. I'm able to fix these FPS drops by turning off my VR headset for about 10 sec and then turn it back on and with about 1/3rd of the time the FPS is fixed back to normal. If the FPS isn't fixed I turn the headset off and on again until it is fixed again.
Every time I have one of these FPS drops I noticed that in task manager my GPU usage goes from giving 70% to DCS and 30% to my VR application > to 30% DCS and 70% to my VR application.
I have noticed that this problem occurs more frequently in busy servers where there are a lot of players or a lot of enemy moving AI. But it isn't constant on these busy servers. I can just fly a little bit longer than normal until I get this FPS drop. I also have days where I play on a full Growling sidewinder PVP (for an hour) server and I never get any FPS drops.
I have already tried several things:
I don't know any other possible fixes i can do.
I've attached a video showing the FPS drop. You can visibly see when it starts to lag and as well as see at the same time the GPU usage of DCS drop [note that when i stopped recording i turned off and on my VR headset for ~10 sec and the FPS went back to normal as well as the GPU usage went back to 60/70ish %]