I haven’t found out why it happens and why it sometimes doesn’t happen but during some games if the King Krush Pet is active some boards can’t be interacted with. Nothing happens if you click on the things on the board. And then it works during other games.
I thought this is caused if you interact with Krush first before you interact with the board but this doesn’t seem to be a factor.
Were those older boards, like before Year of the Wolf ones? 
The thing I do know is that the board interaction always worked on the most recent one. With the flowers and eggs and the dino tails.
I’m not that familiar which of the older boards belongs to which expansion but the one with the griphon in the right corner does not work. Also the Ragnaros looking one doesn’t work as well when Krush is active.
So yes, it looks like the older boards are having an issue when Krush is present.