Yesterday I was on the way down to RJP and a friend sends me a message and asks to join. The party leader I'm with is seeming like a bit of a dick, so I decide to go solo at the end of a level and invite him. I go solo by the elevator, but before I get the chance to lock the party and go down my party fills up with randoms.
Today I jumped in a random on the FSC gate and ended up joining some party at Basil. I have no idea who was in it because I got booted while loading, and then once I loaded I got a bunch of randoms joining. In the same run I went solo at the start of D25 because someone else in the party wanted to invite a friend, and just a few minutes later on the same level a friend ported down to me and the party filled up again.
Did the anti-looping party lock go away? Does the game just really, really hate to see me dungeoning alone?
You can press F6 while loading and lock the party so that does not happen.