Voice search - results play in Google play music

[Tiwas]

Plan

Premium

Device

Samsung Galaxy S9+

Operating System

Android 9

My Question or Issue

Whenever I use voice search the results end up playing in Google play music. I've set up Google so that Spotify is my preferred service. Is this a known problem? Anyone have any good tips on resolving this?

I've tested in both Android Auto and by invoking the "hello google" function. When I use "hello google" it will prompt me for which service to use, but in android auto it will switch out of spotify and into google play music.

Thanks!