The cards were still green but when I clicked on them nothing happened, I could not even hold them up below the board and wave them around with cards like you can with cards that aren’t green.
They were Worgen Infiltrator and Sneaky Delinquent
There is a bug with Freezing Tap against all classes and cards. Hope the developers will notice this.
Already noticed and being worked on. I am not sure how good the suggested workaround is: