Morning, Dave,
I now have the TGS Display utility working! A simple solution that I should have thought of before - "Run As Administrator". I bet its mentioned in the manual, too. I will refrain from moaning about recent versions of Windows being so pointlessly complicated . . . oh, I just did.
So the next stage now is to wait until a small airport fails to offer visual guidance. This may take a little while. And, thinking about it, I don't think this has happened recently so the issue might even have already been solved by your guidance on settings. Time will tell.
Best regards,
John