VLC Player

I am not sure whether this is a Windows 10 issue or VLC player, which is why I ask the question here.
I have a number of PC's and on each one when I full-screen VLC player on all the PC's except one, the taskbar is not visible. On one it is visible though. As far as I am aware they are all set up the same and I am not sure where the problem lies. It seems that on one the taskbar is on the top of the fullscreen on the rest it's behind vlc. Anyone know what the problem is?

It is in Fullscreen. But for some reason on one PC the taskbar is accessible and not on the other pc's. I am completely confused by the difference. It works on two pc's but not the third.

No, alas it is not resolution. I have no idea why but the taskbar remains on top with VLC player on just one PC. It obscures part of the video. I tried wiping VLC off the machine, which worked correctly because all the settings were reset, but it has failed to fix the problem. I am however starting to think that this is a problem with Windows and not VLC.

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Correction! It was a VLC issue. I have no idea how I fixed it, but it has gone. LOL!

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Never mind, lol, it's not solved. However, I did find ONE post on the internet that mentioned that this is a problem can happen with VLC on 4K displays. I downloaded a different player and the issue has gone. I guess for the moment just have to accept there is a bug in VLC.

For VLC to get the truly full screen experience, you need to do two things:

1) Press F11 to go full screen - note that the drop-down menus and toolbar at bottom of screen will still be visible.
2) Press CTRL-H. This will hide everything and give you a true full screen experience. Press ESC to exit this mode.

OK I solved it.

The solution was to solve another problem I had with the 4K display. The display is 3840x2160 but it also supported higher resolutions. I wanted to get rid of those higher resolutions because they cause confusion in applications. Today I found out how, using an EDID editor and low and behold the problem with VLC went away too. It seems that driving a monitor or TV at a resolution higher than native confuses VLC player and it leaves a one pixel gap around the display which is enough to access the Win10 Toolbar.