[Redeemer Prime Broke]

I had the same issue last night while trying to level up the mesa prime and the new prime weapons. Doing dark zone survival on Eris at about the 11-12 min mark quick attacks would only show the holstering animation, and going into plain melee mode would result in nothing happening. This occurred on 3 out of the 5 runs I did. On the second run I stayed in until about the 19 minute mark, but by then my secondary got stuck and I had to use peacemaker as my only means of defense. Eventually all animation stopped and I just hovered to the exit.

From my experience it seemed related to being grabbed by an ancient during a particular frame of animation, but I was never able to find the exact trigger.

Not sure if this is related to the previous Mesa melee bug that I saw a few threads from 2015 about while trying to find info on the issue last night, but it sure seemed similar.