Minions get stuck outside arena when fighting Jamanra, The Abomination

I'm busy with endgame on Dawn of the Hunt with Lich. When doing the Copper Citadel, my minions would on occasion get stuck outside the arena. I play in party so I can't pause to resummon them. The result is that I have to fight the first phase without most of my minions. They respawn when going to phase 2. Please fix.