Since the last update the snowballs no longer hit the first enemy. I can't quite make out the logic but it does eventually hit an enemy, just not the one in front. Sometimes it skips several entire waves before it finally hits enemies. This is on my custom map. It happens most of the time. It does not seem specific to a certain type of enemy, though I've never seen it skip a boss (even though some bosses are immune to snowballs it still hits them with no effect). I have not attempted to reproduce in other maps because I usually just play my own custom ones.