I'm using bluetooth earphones with a dedicated assistant button to control my Pixel 2 XL. If the screen is on I can get Google Assistant to control Spotify. However, if the screen is off and I try to tell Spotify to play a song Google Assistant responds to me saying it will play the song but Spotify doesn't do anything. If I then turn on the screen and unlock the phone I'll see my request processed in the Spotify app, i.e, the song graphics pop up on Spotify, and then the song will play.

Anyone else have this issue or know how to fix it? Note that I can get Google Assistant to perform other tasks like set a reminder when the screen is off so this just seems to be a Google Assistant - Spotify issue.

I'm using the latest version of Spotify (8.4.46.575) and Android 8.1.0