Thralls keep disappearing

Game mode: [Online]
Problem: [Bug]
Region: [EU 1031]

Fix the game asap Thralls dissapearing without reason i have them placed in my base no one attack they was full flawless and legendary weapons named thralls i lost 2 they vanish…

Steps on how to reproduce issue:
1.Place Thrall
2.Move Thrall to a location
3.Thrall was there for 10 days
4.Today thrall was there and after 2 mins Vanish… in front of my eyes…