XP bug in team missions:

Your team splits taking down several mobs. Now, if your kill two mobs at about the same time, you will first get the xxx can loot, and no XP, then when you complete your own kill, you will get XP for the other mob and your own.

Now, if your team split in three... You will never get XP from the first kill, only the second and the third. Sometimes not even from the second... Something is bugged here, and this description of the bug should ring a few bells at FC