Airplay display not working

When I select the menu item 'disconnect airplay displays' I get only a partial disconnection. The display showing on the TV connected to the Apple TV ceases to show the image on the MBP. That is fine. But the icon remains blue, and the menu shows the Apple TV still selected.

When I go to displays on system preferences, it is not possible to move the display from the Apple TV to 'off'; while i can select 'off' as soon as i release it, the menu switches back to the Apple TV item.

The consequence of this problem is that I cannot then reconnect the desired display, as it is not possible to select any other menu item than the Apple TV (which I had been attempting to disconnect).

So far the only means by which I have been able to resolve the problem is by restarting the laptop.

Can anyone advise how I can get the Airplay display to work as it should?