Hello.

First, excuse me to maybe not use right names ect, usually i play on german client but for lack of ppl talking there i write it here. Also sorry if already posted, i cannot find it.

During the last days when doing CM-runs (not Preatorium), at the second or third boss (Magitek Colossus Rubricatus) sometimes it happens during 50% of his HP that he starts to get "immune" to physical and magical damage. All attacks only do 1 DMG from now on.
Now many ppl always start shouting "Its bugged, lets die and repeat". Most times it helps and the next try the boss can be killed nomally. While it really looks like its bugged because one cannot damage him anymore (besides the 1 DMG per hit) and no matter how long of waiting this doesnt stop, im still not that sure its really a bug.