Image in 1-channel view no longer fits to panel

[tc2709 0]

Hello everyone

I have a GV-1480 and have been using different versions of the GeoVision GV boards during the past 10 years or so.
Currently I have the Geovsion 8.9.1.0 Software installed.

Generally when you click on one of the camera images on a multi channel view, GeoVision will go to single channel view and show only the camera you clicked.
When you click the image again, it will go back to the multichannel view. I use this feature quite a lot.

The problem is that my son accidentally clicked around on my computer a couple of weeks ago,
and after that when I go to single channel view, the camera image no longer fill out the whole panel (see images below).
In the ten years I have been using the GeoVision Multicam Surveillance System Software, I have never seen this behavior.

This is what it looked like before my son clicked around on my alarm PC.
(note that the screen dumps below are borrowed from the thread "topic/25501-not-full-screen/" since I can no longer show full screen/panel in single channel view).

 

And this is what it looks like now

I have tried just about everything to get the image to fit the panel again.
It looks like the PC display settings and the GeoVision display settings are the same as before,
and this weird behavior does not seem to be affected by these settings anyhow.

Can someone please help me with a resolution to this problem.