Why is child with "min-height: 100%" taking no space, when parent clearly fills out the screen? [closed]

I have a section element that has its min-height set to 100%, but its not taking up any space.The parent (main) clearly has a height of 525px.

I don't know if its relevant, but the parent is a child of a flex container, and its height is set from "flex: 1"

Parent element:enter image description here

Child element:enter image description here