Hmmm... The intrinsic content size height is definitely not zero, because everything works right now.  The overlay view uses as its intrinsic height the height of a UIButton (one of its subviews).  The intrinsic height never changes so it doesn't need to be updated.

I think this is fine since it's working correctly, if someone wanted to make it dynamic they'd have to move the constraint from install to update, but that's true of the rest of our constraints.