Usually the chat server will consider you as having left all rooms maybe 10-20 minutes after you close all chat tabs. I don't think Chat has been doing this for a couple of days, and there's several signs of this.
- Whenever I enter a room in the morning, it's the only room I'm in, and I have to join others or click Rejoin favorite rooms. I didn't have to do that this morning; I was already still connected to all the rooms I was in last night.
- Actually, I was already in the list of joined users this morning, very well faded out and on the second line of users. (I have not kept a mobile device connected overnight.)
The RPG.SE chat room has an awful lot of lurkers in it, usually these people don't stay connected, and usually we only have maybe a dozen people at a time tops, lurkers included:
The lurkers go back a full day or more, with that last user on the list showing up as:
I don't know if this is localised to RPG.SE's chat rooms or network-wide. Other chat rooms seem to be experiencing a similar malady, but it's hard to tell as I'm less familiar with those.