I started running into the same thing about a week ago. I’ve got an I9 9900K & 3080ti running my HP Reverb G2 VR. I’ll average 41 FPS through my entire flight from take-off until I land. As soon as my wheels hit the ground my FPS drops to 4 FPS and it’s almost impossible to exit the flight to get back to the main menu. Once I do, FPS jumps right back where it should be. It seemed to coincide with when I downgraded my Nvidia driver from 531.79 to 531.29 per Asobo’s suggestion. I just did a regular installation. After the issues I went back to 531.79 but this time I used DDUinstaller but it didn’t fix the landing stutters. I’m going to try using DDUinstaller again but going back to 531.29 in case there were some leftover files from the newer driver that were affecting it. I’m also on DX 11.