I’m on server 617. I keep losing thralls as I try to get them back to my base. They fall through the game world if my binding is interrupted. Once I did not let the thrall go and he still fell through the world. Taming thralls is basically impossible right now.
Work around is to walk away (out of site) and return. Posts that I have seen indicate the thrall will be unconscious on the surface.
I beat my thrall through the world during the capture period, last hit with the club and buried beyond sight. Single player mode.
Re-log and they will be there on the ground.