Figured I'd add my name as someone also dealing wth the Quest Pro controllers lacking thumbstick usage when using the Link cable via a Quest Pro. I also use the thumbstick for vertical tilt and left/right pagination, skipping ahead 10 secs during playback etc.
This thumbstick issue is only happening in DeoVR via link, other things like games and other PC based software work fine via Link... as does native Quest version of DeoVR, no issues with the thumbsticks there.