Co-Op XP, PXP, and rating not given equally to both players

[Jbrown4400_MLBTS]

Me and my friend played a handful of co-op games together that I hosted. He didn’t receive nearly the amount of xp I did, I’m talking big big difference. And his rating capped out at 100 compared to mine being over 400 as we went 5-0 that night. Is this supposed to be how co-op works or is it glitched? Anybody else experience that?