I was in the spider cave fighting the Queen Matriarch Phase spider and getting my butt kicked.
I drank a Haste potion on my Halfling Ranger who got one round of haste before being knocked on his butt(unconscious). I got him back up (again) in time for the exhaustion debuff from the haste potion to hit. I was like damn okay, so I passed my turn and when my halfling's turn came around again he was stuck in place. I could pretend to move him, but after I clicked end turn he would pop back into place where he had been. Every other action would attempt to complete, but then nothing would happen. He dropped and every time I tried getting him up he just sat there. The only good news was that at least his companion still was active so it was doing its job while my Ranger did nothing.