Why do I get such a low frame-rate in VR Preview? (Pimax 5K Plus)

I tried VR Preview for the first time in UE 5.1. I now have a Pimax 5K Plus headset. UE4 with the Oculus Rift CV1 and even Quest 2 was smooth and fun. But in UE5 and the Pimax HMD, I get 20-25fps. What I tried: Using the XR plugin as Oculus and Steam appear as deprecated, starting a new project with Forward Rendering and without use of ray-trace. My machine is 12th gen I9, GPU is 12G 3060 and 16G of RAM. My RAM could be more but I don’t think my setup would be enough for just 20fps in an empty VR environment. I run the Microsoft Flight Simulator pretty decently. Anyone has the same problem?