I know there have been other posts on this, but none of them have any results and this has been happening for over two months now. This is a bug that arrived in an update around July/August and still hasn't even been acknowledged, much less fixed.
When I'm connected in the car via Bluetooth I cannot use the car's controls to skip tracks unless Spotify's playing screen is open and the phone is unlocked.
If I get a call, or any other app notification comes in over the top of Spotify, then even unlocking the screen doesn't work and I have to pull over so I can make Spotify the current app again.
As soon as the phone locks, sure I can just scan the fingerprint reader to unlock it but there will be a lot of users who still have phones without fingerprint scanners and it's unsafe and illegal for them to be picking up their phones and putting in a passcode or pattern every time they want to use a basic function of the app.
I'm sure I'm not the only person who pays for Spotify on the grounds that they spend a huge amount of time in the car. You're not the only gig in town anymore and you really need to up your game when it comes to responding to bug reports.