Hello Ray,

firstly i suggested that it is likely a problem of the Joomla session refresh timestamp, but this was intended for the issue that you reported regarding disappearing users. That fix was related to change the parameter 'Max inactivity time to strip out users' in the chat configuration that i've already said you to set to 'Use Joomla session timeout'

If you report that new messages need a refresh this is another story. It's more likely the connection is stopped in some way at a certain point, but i've no clue on this.
Eventually you could try to inspect the network traffic using Google Chrome Developers tools when you are not receiving new messages, to determine if the AJAX requests are still going on.

Best regards,
John