The Presenter view in the Surface has been closed (or Surface has been turned off), therefore the session remains launched in the videowall
The room is present in the videowall and there is no apparent way to close it from the presenter device
The room has not been closed correctly before turning Surface off or closing browser Presenter tab.
-Open the room launcher page from any device, preferably from the presenter Surface
-Enter the same code as the room that was not closed
-The room will attempt to launch but as there is one already open, it will not appear in the video wall
-Wait for the Presenter interface to be fully loaded
-Close the session using the icon at the bottom of the page
If the problem remains, create a ticket with the support team.