"stuck" On Quest (spoiler Ahead)

Hey guys, I recently continued the Dwarves and Dogs series on its fourth part and as I got into the stomach of Garaheth I died because of his bloodcells. I spawned in Nesaak, teleported to Maex and went to the portal to go through a second time. All went fine until I reached his heart again, but this time I was not able to freeze his heart.
I can see the green particles and tried everything (yes I used the Staff of True Ice, ofc), but nothing came in result. Can someone help me here?

 

/class, switch worlds, make sure you're left-clicking (four times), or if all those don't work, file a bug report