I checked 3 pages of bugs and saw nothing on this, but pardon if it's a repetition.

*When casting Pillar of Flame on enemy armies, it often reduces their health (say, from 200 health to 40) yet makes them immune to attack, where my unit will be stuck in a running/moving animation until I cancel that order.  This happened with multiple armies, even against a unit I did NOT cast Pillar on (I cast it on one unit and it bugged, then went to attack a different enemy with a separate group of my guys, and they hung, too--I had to reload and simply do without the spell to keep it from bugging).

In one case, I had the bugged army disappear the next turn, so I can only assume they were really killed off and the lowered-health unit was a graphics bug, but even if that was the case, it would not explain why enemies who had not been cast on also bugged.

*A couple of times, my champion whacked a unit and it all looked normal, then the next turn, my champion showed injured, where the previous turn he was not.  The only thing I can think of is the enemy performed a counter attack that did not register (no animation or health loss on that turn); the second time it happened, I noticed the enemy unit was equipped with Boreal Blades.  Wish I could provide more info--the next time I notice it happening, I will reload the battle, if possible, and try to duplicate the result.  I'm sure the many variables make it hard to track down.