DialogButtonBox showing stacked buttons

I'm creating a custom dialog that has its own DialogButtonBox. Each dialog has a property for which dialog buttons to show, and each dialog will have this set at dialog creation (not meant to be dynamic)

I use Loaders on each button inside DialogButtonBox to prevent creating excess visual items (the application will have a lot of these dialogs)

The DialogButtonBox Buttons are showing stacked in the same position, making it impossible to click any of them.

In my application, this is working correctly except in specific cases where the dialog is parented to a button inside a ListView/Repeater inside a ScrollView.

However, I was able to reproduce my issue with a small example that has just a basic button, so I've attached it as MinimalExample.zip