GUI not scaling based based on screen size (looks very small on larger screens)

[1337GameDev]

In the editor, I am designing my UI, and it doesn't seem to scale when I have "Maximize on play" selected, and fear it won't scale on my target device sizes then too.

The Scaling Style is set to Flexible and I have set up anchors...

What do I have to do to have things scale?
Does it matter if I have subpanels under the main panel for my UI?

[ArenMook]

Flexible = whatever the size of your game window is what will be used.

If you want it to scale, use Constrained.

[1337GameDev]

I tried that, and it seems to scale the entire UI as one unit, so on desktop, if you change the width, the entire ui scales smaller (including elements that are supposed to be anchored to the top of the screen).

[ArenMook]

Constrained = fixed size. If something was 1/3rd of the screen at 1080p, it will still be 1/3rd of the screen at 360p. Width doesn't affect it unless you change what it's constrained by.