Friend and I prestiged my Karax and his Tychus. At some point between level 1 and 5 (6 for him) he got ahead of me on EXP. We reset to 1 at the same time and did not play without one another and there were no disconnects. He was between 9-10k EXP ahead.
There’s a “First Win of the Day” bonus that grants 10k exp. This is probably what’s causing the difference, if you played a game earlier in the day.
TY, can confirm that’s what happened, can delete thread.