I faced a willbreaker that took every creature I had each turn. During an event. So I then play tested the card and was able to duplicate the situation. I did send a support ticket, with screen shots. I disabled my cards in hand so as not to cast supports or spells.
Wait, so what is the bug? As long as you keep casting spells/supports you should be able to take control of every creature every turn.
Unless you’re saying it happens automatically every turn with nothing cast, which is definitely a bug.
What event were you playing, and at what point in the turn did the bug trigger?
In ai nodes the turn start action is counted as a spell. As so even without spells willbreaker get opponent creature automatically .