I don't know why it's not working, but it's just not launching correctly. If I lock my Pixel and then put it on my charger, it launches the app, as I can see the always on display is doing something because the text gets thicker, but the text reverts to the always on locked state and the app doesn't open on the display but just in the background.

When I then unlock my phone, the app is open, and the auto quit doesn't function anymore.