Can’t use Siri to play Spotify while in Driving focus

I recently bought a car which I can connect to my phone via Bluetooth, so naturally I assumed I’d be able to use voice commands while driving, and driving focus activating automatically when connected to my Bluetooth seemed like a perfect combination - I can get my phone to change playlists etc but I won’t get any distracting notifications.

I was driving earlier today and asked Siri to play a song from Spotify and Siri’s response was ‘you’ll need to unlock your phone to do that’.

Not only did it do that but it then stayed on the unlock screen permanently, so I had to pull over and unlock it so I could relock it. Thankfully I was on a quiet road but if I’d been on a major one this distraction could have been incredibly dangerous.

I have Siri set to work when locked as I use it like that all the time - it seems like driving focus disables this feature altogether?

Wondering if anyone has any solutions to this issue that will allow me to control Spotify with Siri but also act like driving focus in all other ways (including activating automatically when connected to my car)?

It should also be noted that my steering wheel does have a voice command button but that interacts directly with my car and not with my phone so I can’t use that to bypass Siri.

thanks in advance