GridPanel not scaling properly

[Faze_Kaas]

Hi all,
I have a GridPanel with 8 borders that have a gap between them:

But the gaps dont scale correctly when screen size changes:

How can I fix this?
or is there a better way to make gaps between borders that do scale properly?

Thanks help is much appreciated

[Faze_Kaas]

Spacers or padding also dont scale correctly, anything else there is to try?