Teamviewer connection not working

Have teamviewer host on a machine at work, has been working well for a few years.

Being host, the session ID and password is always the same.

Yesterday, I had to strip and reload windows onto my PC that I use to connect to the machine with teamviewer host. Reinstalled teamviewer, snd when I try to connect, it is now giving me an error message saying 'Session code expired'

I have restarted the machine with teamviewer host, and clicked on it, and the session ID is what it normally is, but still getting the error message when connecting to it.