Quest 3 always CTD, Pico 4 is fine

Just acquired a Quest 3 cheap, hardly used, works perfectly in stand alone. But it is hopeless in Meta streaming only PC mode, cable or airplay, the image is shaking around and shaking black borders, that cant be right? Using Virtual Desktop with the Quest 3 the PC desktop is stable, and FSVR does start a flight but quickly CTD? However, I still have the Pico 4 and it plays FSVR, and so far has never CTD. I don’t use Open XR toolkit for either Quest 2 or Pico 4, I hardly notice any difference in quality or frame rates. Just to say for the few seconds that the Quest 3 does play FSVR, the image does look brighter and a little sharper than the Pico 4, but the Pico 4 is a lot more comfortable than the Q3. Must be some settings for the Quest 3 that is not right?