I am not sure that it counts as a bug, but combat ending when enemies are still present, but disabled, is very annoying.
Here is an example: my mage was fighting the final match in the arena, and made the mistake of putting Carnifex into a cryostasis, in order to try to shatter him via cryogenic induction. Instead what happens is that combat ends and a few seconds later starts again, initiatives get re-rolled and Carnifex wins. I am a slow player - which is why I like turn-based combat - and I honestly don't have the reflexes to react in situations like this (assuming there even is something that can be done).
As it is, this feature makes certain strategies - like cryostasis shatter - not very viable. And that's not very fun; after all, what is the point of shattering enemies into hundreds of glittering pieces if not winning arena matches?