Party bug

I was in a party today to do a trade. When I left the party, we then rejoined then disbanded again. After we disbanded it clearly showed we were not in a party but we could still see each other in act 2 cruel in the forest area. We both were like huh? Once we logged out and back in it seemed to fix it, but clearly there was some party bug.

I have noticed that you have to give the instance time to reset, though from what I have read, there is a way to manually reset it so you don't have to wait. Logging out/in does not necessarily work every time...