Last night I joined someone coop boss. On the first hit of the boss, it said "Boss being attacked by someone", so I attack again. As the result, the attack became the 2nd attack which does not give me extra XP for joining the coop boss at all I checked the XP gained & #attack stat and only have like 60XP gained( I hit with 1stamina) and #attack=1. BTW, I'm not yet at my max help on coop boss because before&after that bug happens, I'm still getting full XP for joining a coop boss :\
