I had a similar issue when I first tried to use my PCL. It turned out that the headset didn't like to compete for DP access on the GPU card when loading DCS. I had two monitors connected, so after disconnecting one, the PCL worked fine. Then I was using an RTX 3080, but now an RTX 5090, but still only use one 5090 DP for Pimax and one for one of the monitors, while using the onboard graphics for the second monitor. Also, try lowering all your DCS settings to base line first. Further, If you have OpenXr Toolkit installed that may be a problem too. If you have, then untick DCS in the toolkit companion. If you have OpenXR layers, you can move OXRTK down the priorities and re-tick DCS in the companion if you still want to use the tookit.
May not help, but hope something here may point you in a useful direction.