Board Game Arena

In my current game I want to play a tawny owl and gain the bonus. My understanding is that I need to pay with 2 cards that have the same symbol. At the top of the screen there is a red x which does not change even when I select 2 cards which have the same symbol. Is this a bug or have I misunderstood the rule?

screenshot/game table and which move?

https://ibb.co/jyydysT

409775873
Move 53

I've selected 2 Douglas fir in the screenshot but it's the same when I choose other cards with matching icons.

They should have the same symbol as the card you play (which is not the case).

Ok thanks. I thought it was just the discarded cards that needed to match.