Shard of Power x Masked Bandit

[Offspring]

It happened yesterday, two times in the same match (Custom game, SD Offspring x SD Unfurl, turns 6 and 7):

Once you have Shard of Power on the table, and also Masked Bandit, when you end your turn, and Bandit isn't damaged, he will turn back to your deck, as if it was damaged.

I think its a bud because his ability says that he is put back on the deck at the end of your turn if he is damaged.

Thx in advance.

[Gondorian]

He was definitely undamaged before you played Shard of Power, right?

[Offspring]

Yeah, both them were undamaged
The second one I just cast it on my turn while I already had shards on table, and passed turn, then he got back to deck too