How many times we have to repeat a mission with Raging Fires during Hero of Rathleton Quest?
To gain access to the room with mechanical creatures and then directl to the Professor Maxxen we have to kill several Raging Fire
and put the corpses into the machine.

Even though we do everything according to the spoilers sometimes it doesn't work. We have to repeat this part of the quest even a few times before it starts to work. My question is:
How many times we have to repeat a mission with Raging Fires during Hero of Rathleton Quest?
Is it random? Is it always the same amount of times or maybe it is simply bugged and it should work on the first try?
source: https://tibiopedia.pl/quests/Hero_of_Rathleton_Quest