There is a cave on Elizarovo island southeast of the Sakhal mainland. The cave is on the east side of the larger island there.
I was crouch walking into the small cave to see what was in there, there is a rock shelf inside with a skeleton on it. When crouch walking back into the cave my character got stuck and I was unable to free myself. I could not lay down, removing my headgear and weapons didn’t help, and leaving and rejoining the server also did not work.
Eventually my friend decided he would knock me out so I could crawl out but I died immediately from his punch with no reasonable explanation that we know of.

If you walk full height into the cave you don’t get Stuck, only if you crouch walk.