Hello,
Can you please send a video of this behavior? As far as I'm aware, this passive should trigger at the end of the round, which *should not* allow Utakata to perform the mystery in round 1. We've tested this before, and that was the behavior of the ability. The passive triggers once the round ends, but before the new round begins, allowing player input but not allowing the mystery to be executed, which is how it should work. If you've been able to execute the mystery during round 1 (before it ends), that would be a bug, and it may have simply been corrected in a recent update.

Please let me know, thanks!

Unfortunately, I can't speak as to the priorities for fixes. It may be that some fixes are just much easier than others, which is why they are done even if they are lower priority or "less important."
Sorry that this inconvenienced you. :(