Abyssal Depths Lich Bug

Hi there, I was doing an Abyssal Depths on my Holy Fire totemer in a T4 map, and spawned a Lich. The first phase was fine, cleared the first Spire. Going back to the Lich phase, the Lich randomly disappeared instead of spawning an opening to a second room with a spire. I could not use my character to leave the boss fight room. I logged out and in, went back into my map and to the depths, and the Lich respawned at the entrance of the depths. I dps'ed the Lich and it disappeared, and I ran back to the boss room, and the encounter continued as normal.

This just happened to me too. Holy flame totem here. After second spire boss disappeared