Position sticky doesn't work inside container

Hey everyone,

I’m trying to make a sticky div, but for some reason, it doesn’t work when inside its parent container – it only works when directly under the body. I have:

  1. Set a position value to the top of the sticky div
  2. Checked that its parent elements have neither a set height nor overflow hidden/scroll/auto

Any ideas why this might be? Here’s a quick screen capture to demonstrate. Any tips much appreciated!