Button always displays on top in FrameLayout

Question

I have FrameLayout like this:

Answer 1

This answer

Buttons in Lollipop and higher have a default elevation to them which causes them to always draw on top. You can change this by overriding the default StateListAnimator.

Try putting this into your button XML:

android:stateListAnimator="@null"

The FrameLayout should now cover the button.