It seems their report is not accurate, its a session error, and the server pushes a timeout timer due to a session error somewhere and then you only see the session issue, not the timeout message. It seems the portal cannot see the difference between a player caused session change on the server, or a session change created by the server itself. Only a session change in general and that general message is, that your session is not the most current one, so the client assumes another one has to be, while no other session exists, only the internal server issue.