Hey there! I sent a ticket to Oculus support, and am waiting for a response, but I figure I might as well go on here and ask:
For some reason, the thumb presence detection is super wonky on my right touch controller for my Oculus Rift S. Whenever I use the trigger with my index finger, it bugs out the thumb presence detector on the controller and continues pressing it down, even if my thumb is off the A and B buttons and the thumbstick. It detects when I press the A and B buttons just fine, but when I let go of them, it moves my virtual thumb STRAIGHT to the thumbstick. Is anyone else having this issue? Please let me know. Thanks!
EDIT: When I say "press" regarding the A/B/Thumbstick, I mean just placing my thumb on it, not actually clicking it down.
Well I'm also having the same issue with the persistent phantom thumbstick touch. Same as you, when I touch the A B buttons it detects the touches but my "virtual thumb" immediately returns to the thumbstick. Did you manage to fix it?