XP Discrepancy

So a friend and I decided to roll new toons on Daggerspine and level them super-casual. No Heirlooms, No Instances, just 100% questing. After a couple of days, I noticed that my friend is consistently ahead of me in XP by anywhere from a couple of bars to an entire level, even though we were doing the same things. Yesterday we were on Discord and we turned in a quest and he says to the NPC “Hey thanks for the 5K XP” Wait a minute, you got 5k xp? I only got 4500, what gives? He assured me he didnt have any heirlooms on and he didnt have any rest xp left on his bar. What else could it be? I had him report his xp for the next several quests and I noticed that EVERY quest turn-in gave me 10% less xp. What could possibly be causing this? I’m getting tired of having to go kill extra stuff after he logs off to get caught back up with him. I started joking that the gender income gap must exist on Azeroth as well :roll_eyes: