Xbox one X Unable to knock out thralls

Game mode: [Singleplayer]
Problem: Bug
Region: [Europe UK]

I can no longer knock out thralls. I was able to do it a few weeks ago, but I have no idea why this is the case. I can do enough damage to kill them with a 1 damage club and they still don’t get knocked out. This is a real problem for a significant part of the game.

I don’t know how to reproduce this. It just stopped working, and the white KO bar has completely disappeared. Even after re-installing the issue persists.

Steps on how to reproduce issue:

Just checking…are you able to see health bars and nameplates over NPC heads? I had a similar problem- I was not able to see any of these things- and found out it was because I had a second controller plugged in. Although, I have no idea why you wouldn’t be able to knock thralls out (sorry).

Yeah, I can see the health bars and nameplates, and don’t have a second controller plugged in. The white bar just vanished one day, and i’m really not keen on resetting and losing all my progress, especially as it may happen again.