Ok so I beat Gonarch in the big wide open area, then went through the extremely annoying 60 minutes of running through tunnels and ♥♥♥♥ where she is invincible. Then I got to the part where you finally start doing damage to her again. Then we went to the next stage where she falls / jumps down to the next level. Then she started spamming green ♥♥♥♥ everywhere, and I have been circling her now for like 30+ minutes, shot every rocket given to me into her, shot every single bullet, every single crossbow bolt, every single satchel charge, every single grenade, etc....I've now used up all my ammo and have been circle her for 30+ minutes, and she is still going strong. I watched a guy fight her on Youtube video, and the part I am stuck on he finished in 3 minutes....just using the supplied rockets (which I've run out of, plus all my ammo from every other weapon). My aim is not bad, every single rocket hit her square in the belly, plus all the other ammo I shot her with. Is there a fix for this bug?

Just an update, after fighting for almost 30 minutes, I finally died....Upon the automatic reload (before I used up all my ammo and at the very start of this stage), I shot Gonarch with about 4 or 5 rockets and the stage ended. This makes it 100% certain my game was bugged to ♥♥♥♥. Wish I had known dying and restarting would make the fight last 30 seconds instead of 30 minutes.....

hmm i have no such problem. i will replay and see whats going on and then i will report back.

I also have this bug lol

Same issue. Had to restart the fight and that time she didn't get stuck.