@garrettzatlin there was a thread with some solutions, I don’t remember and I don’t have time to search.
But maybe you can do something like that.
You subscribe a logged-in user to a realTime channel that is based on userId.
On new login you first send a message to this cannel to logout and then you subscribe the current instance to this channel. This way if a user logs in it’ll log him/her out of all other sessions.