Sorry, they are both the same level.

To add more details, Popsiclestick was in the zone soloing and Hatoko invited from East Altepa to join.

It looks like Signet was just not working for Hatoko, to me, and not functioning for the experience points buff. It might be advisable to check experience points between characters if you do not use sync. (I should have tested using sync to see if the XP had changed.)