When will onroomlistupdate() be called?

When is the onroomlistupdate() function of PuN2 called? Isn't it called when the room list is updated? But after Deug, I found that it was only when I called the JoinLobby () function in the initial Login (). I created the room without calling it, and then I called LeaveLobby () in LeaveRoom (), and then called JoinLobby () again.But it's still not called