I just discovered this phenomenon, though I personally started doing it back in 2018 after my abusive parent visited and further traumatized me (and I've had chronic nightmares ever since). To prevent me doing this, I slept for years with a wrist brace and body pillows. But I also majorly overheat at night so a few months ago I stopped using the body pillows, which were trapping heat in the bed. I then discovered I was sleeping on my wrist braced hand and painfully bending my thumb under me, so I quit using the brace. Now I'm sleeping with Trex hands which is causing wrist pain. God why is sleeping as an autistic person so hard in so many ways?! I also have c-ptsd which really doesn't help. Anyway just a PSA for those who don't know about it.