Not sure how helpful this is, but if you hard shut-down the computer and reboot it, that will work. You can also login to your TeamViewer account from anywhere, remote in to the computer, and turn the screen back on, and enable remote input.
Thanks! Rebooting the computer actually did not work, BUT I have the TV App on my phone, so I was able to log onto my home PC from that, break the connection, then access my work PC. Thanks for the suggestion as I hadn't thought of that. Problem solved and lesson learned!
In such issues I think it is worth to check if the TemaViewer display driver is installed. It can be checked it advanced settings tab.