What you were expecting to happen, and what actually happened:
_This is simply what you were trying to do and what happened instead.
I triggered Ubastet and he killed one troop but didn’t kill the second troop. In the screen shot the second troop was Elemaugrim.
How often does this happen? When did it begin happening?
It has happened in pvp twice tonight. It has started happening after I updated the game. I use Ubastet a lot and this has never happened before tonight.
Steps to make it happen again
I don’t know of any steps to make it happen. It just happens when I use Ubastet.
Was a hero present on any of those teams? There is a hero talent that gives a barrier on ally death. This barrier goes up in between the “Ubastet does damage” and “Ubastet kill!” steps of Ubastet’s spell.
Honestly, you really had bad luck on the second one but I find that choice to be annoying. The Hero talents are so unbalanced and that’s one of them. Yet old before fixed Ubastet would have killed through the Barrier anyway.