SeverFault has Meta.SF and Chat.SF.
StackOverflow has Meta.SO and Chat.Meta.SO.
SF Chat, if I understand correctly, uses SF login.
SO Chat uses Meta.SO login.
Took me awhile to realize the differences.
Is there a reason to have two different setups?
Seems confusing to me. I'm still new to SO, and this is my first post to M.SO. So although I have the points (barely) on SO, I can't chat because the points for chatting on SO are from Meta.
I understand Chat is in Beta. So it may just be trying different things. Just hadn't seen anything explaining the difference in hierarchy.