Zalmarath the Colosus becomes impervious to damage

After the latest patch, on PS5, attempting to kill Zalmarath, the Colossus, he becomes invincible and takes no damage after a point. I have fought him multiple times (and died) and sometimes during the fight (not all of them) he stops taking damage. 4/6/2025

I'm also having issues with Zalmarath, on PC:

Boss becomes impervious during the fight, seemingly at random. My attacks just pass through him and he cannot be damaged at all, until I reset the fight.

I fall through the floor in the arena. Seems to happen when I roll near the edge and/or when he does his arm sweep attack.

These have all been issues since at least 0.1.

Also this is a design issue, but none of this boss's attacks can be parried. Not even the adds in the second half (the cold explosion spinning robots) can be parried. So there's no way to build up frenzy charges as huntress.