I am also having the same issue since the last update. I have the HTC Vive Cosmos Elite and can confirm that the menus seem fine, well, stuttering like normal, but working. As soon as it goes to VR the headset just displays the grid area while the monitor displays the two lens VR view flickering like mad. After about 20 seconds the game just crashes to desktop. It did work once, in a bush trip in the cessna 172, but with any custom flight, just crashes. Tried some std edition aircraft models and bought ones like the T45 Goshawk, also tried std airfields instead of upgraded ones… all the same… no VR working except menus.
For reference:
I9 9900K
Nvidia RTX 2080Ti
128GB Ram
Vive Cosmos Elite
Windows 10 Pro (up to date)
Latest Nvidia Drivers