Not sure if anyone else has noticed this, but the party system just seems to have a small bit of a bug when you disband parties.
Namely, add some people to a party, then without removing them from it, disband the party. It’ll throw up a nice error message and then when you make a new party the people seem rather bugged out.
I think I remember this being a thing a while back, I just wanted to note it was still a thing.