Reef Map Boss not phasing

Hi

the boss of Reef-Map does not phase properly and is stuck in his add spawn cycle. This is making the map uncompletable for me. I have tried 3 Reef Maps so far with the exact same result.

Any help is appreciated, thanks
Magz

Same here. I've done 5 at this point, and every time he gets stuck in an invulnerable phase.

same, maven witness reef boss stuck in phase 1

I am having the same problem tried it with maven and without and the boss always goes in the shield phase and stays there

I am having the same problem, the boss gets stuck and the map can’t be completed.

Still broken - not phasing.