Mei The Blade Thrall Not Taming

Game mode: [Online]
Problem: | Bug | No taming
Region: Swamp

I already have one of the same can you only have one named thrall? It seem it keeps reseting somewhere during the day, haven’t pinpoint when.

Steps on how to reproduce issue:
1.Put thrall on lesser wheel
2.Add gruel for 2 days total amount
4.Thrall progress reset to 25% from around 90%