Serpent Trap Echo cards bug

[Clanzy]

If you play doomed Echo card (happen with Blood Eagle (BE) once) and opponent has a Serpent Trap (ST), you will trigger the trap, but it will not destroy any unit.
In my situation it was so: I played ST in R1, opponent played BE for first time and my ST worked. Then I played Iorveth, took ST in hand and played another trap. In R3 I played ST and my opponent played BE again and this time my ST triggered but didn't work. Don't know which part exactly causes this bug. Is it Iorveth, or Echo, or BE or all together, but this bug unironically cost me a game. CDPR fix pls.
Don't have any screenshots because I was too confused to do anything.

 

[croloris]

I would imagine this is a Serpent Trap / Echo card interaction. I have successfully used ST in past patches on separate rounds, and on copies of the same card.

Just to make sure it wasn't user error, your opponent did have a unit on the board when Serpent Trap was triggered, correct? Because ST doesn't count units until they are played on the board.