I say something like "ok Google, play Radio 4" and it responds saying "Playing Radio 4 on TuneIn" or I say "ok Google, play Bruce Springsteen" and it responds saying "alright, playing the Spotify playlist called This is Bruce Springsteen" but then does not start playing in either case.
I check the system by saying something like "ok Google what time is it?" And it always responds to that correctly.
Very occasionally it works and starts playing the music but more often than not it doesn't.
I have tried:
Disconnecting and reconnecting my Spotify account
Disconnecting and resetting up Google Assistant on the Sonos
Setting my default device to play from in Google Home as the Sonos One
Checking my default music service in Google Home is Spotify