iOS in car handsfree, web player screen pops up

[juhv7f-_3a0fl]

Every once in a while while listening to Spotify app on iPhone (latest iOS version) in car connected via handsfree, the music will stop and the Spotify app has a screen saying something about web payer, do I want to contonue with web player or play on this device. When I select continue, my current song and playlist is stopped and some random music/playlist (not my own) starts playing.

Does anyone know why this is happening and how I can stop it from happening?