Filux was hosting, I was a client, both Linux-64. He set the game up with rejoin, and I joined his running game later.
I then disconnected and was replaced by a CPU. And reconnected.
Then Filux' network player list looked like this:

And mine looked like this:


So the CPU which replaced me in the slot I was previously playing in had inherited my UUID, which I don't think it should.
Additionally, for me, the CPU was not listed as
*AI* but as
???. I guess
*AI* is already not so great (
AI6 would probably have been correct) but
??? is definitely wrong.