XP bug in endgame?

My level 63 smith of kitava gets no xp and loses greater xp on death than what is possible. I know this can be seen as me complaining because im bad at the game but ive levelled many other characters in endgame just fine its just when I try using the smith it does it. like I lose 30% xp on death and i also dont gain as much xp as others. I'm running maps with other people and theyre higher level. level 77 and 90, the guy whos level 77 has had 2 level ups before i've even gained 30% towards my next level up. I've been neck and neck with this guy the whole time. I'm not sure if theres a certain mechanic that I'm missing in endgame I've never bumped into before or if it is simply just a bug but it makes me not even want to touch this character anymore because I cant level up to get all the passive nodes I want/need for my build. the other thing is also the 30% xp loss on one death. im pretty sure I'm not crazy and 10% is the cap but that kinda frustrated me, we were running maps for awhile and being sent back to square one after all that time kinda killed my motivation to play this game anymore