We played recently; at the start, I had version 3.52, and my opponent had 3.63. We both finished on the updated version 3.64.
Both of us experienced a bug: in battle, neutrals didn't attack the stack within their attack range (even if it could be killed with one hit), but continued moving forward. Since we were both playing as Inferno, it was unpleasant. The bug occurred for me both before and after I updated the version. Or is this not a bug? :)

Something similar happened in SoD (Shades of Darkness). I was just discussing similar cases in a stream. There was a moment when a neutral didn't attack the nearest stack because it would have killed itself. Or sometimes (I noticed it in Naga battles), Nagas don't attack the nearest stack (they shouldn't be afraid of retaliation), but move somewhere else, as if they have a plan to attack those they've targeted in the next round.
Or, I used an outside mission, and the Mishka (bear) didn't attack the exposed dog and went around it.