My wife and me had the same ''probleme'' she was lv 50 while i was 45... I never logged out in sanctuary before I realize it was giving me rested exp. I wasn't paying attention to that. I think the bonus exp from rested exp is 100% more exp. Now I log out in sanctuaries. Sure if you spent your rested exp in other class it mean you'll get less from your main class. hope I helped