It That Was Esh/Tul Boss Fight - Both Bosses Immune

Reference Number: 3,743,498,034

During boss fight the second transition never happened and It That Was Esh continued to attack even though the boss was immune to damage.

Tried logging out and back in, but when I re-joined the fight the boss was still attacking and immune to damage.

Yea, got same bug twice today

I've encountered this problem in two out of my last three attempts. It seems to happen when dealing large chunks of damage close to transition phases.