Apple Watch cellular +gps

I got the Apple Watch specifically to use while I run so that I can leave my phone at home and listen to Spotify but it has been a nightmare trying to get that feature to work. Every time I leave my phone the little watch in the bottom right corner of the screen says connection error.

I have Spotify premium and I have set up cellular on my watch so I have no idea why this is happening.

i’ve tried turning off WiFi, deleting and re- installing Spotify and turning my phone off. None of this is working. I highly recommend Garmin watches over Apple if you want to leave your phone at home when you workout as this feature is flawless on garmin watches.