Titan Boss - Minions were doing exactly 0 damage

Hey everyone,

I was just doing the Titan boss with my summoner. Had Arsonist and Raging Spirits, along with Skeleton Warrior and Infernal Hound.

Every time, the fight would start off like normal and I see the damage number for bosses go up, but after about 10% damage, nothing else hits from any of my minions. I see them all trying to attack, but the boss is now taking absolutely zero damage from them.

I tried to use a spell myself, like Unearth, and this did some damage and I could see the counter go up. However, nothing my minions did seemed to do ANY damage to the boss. I've done this fight plenty of times with minions and had no issues, but ran into this twice in a row in 5 mins (after respawning the first time).

I have exactly same problem right now. How did you defeat him? Even my witch doen't do much.