Ohn'ahra possible bug with Feral Spirit

Hello, just played a game using Ohn’ahra and two turns in a row it did not play three cards from my deck.
The first turn it played two cards and then only one card the second turn.
The history bar showed the two cards that were played the first turn with the card back in the third position. The second turn it showed the card played, then the card back and nothing in the third position.
Both times the card Ohn’ahra played before it stopped playing anything else was Feral Spirit.
I think the most likely explanation is that both times my board was full when Ohn’ahra tried to play Feral Spirit. Is this intended or a bug?
I would have thought that even if Ohn’ahra cannot play a card it should still continue to play the next cards from the deck!?
If it’s not because the board was full it might be because I used Triangulate to shuffle copies of Feral Spirit, or some weird interaction with an overload card.
My apologies if this is a known bug

Edit: Ok, I’ve played another game where Ohn’ahra played Feral Spirits on a full board no problem but later didn’t play any cards at the end of the turn (full board again); history bar showed Ohn’ahra playing a card back and nothing else.
Now I’m wondering if it was trying to play a minion and that caused it to stop?