UI Positioning and sizing in Godot
Most important things to understand.
Scroll Containers
ALWAYS set minimium size. Things get squirrely if you don't. If you set children to Vector2(0,0), then the first child that has a custom minimum size will be used (?verify)
Containers
Containers manage children. NOT grandchildren. Unlike CSS.
So if your child isn't showing up in the place you expect make sure the parent is a container. You can inherit if you go container->container->container->node/control
Top Level prop is like "Position: absolute" in CSS
More reading
https://docs.godotengine.org/en/4.1/tutorials/ui/gui_containers.html#container-layout