Car stereo controls no longer function after switch to iPhone from HTC One

[Playmedead]

Title pretty much says it all. Just got an iPhone 6s and can no longer change tracks via Bluetooth connection to my car stereo (Pioneer DEH-80PRS). Worked okay with android, with a few bugs, but still worked. Is this an iPhone thing or an app problem?

[joshmonger]

same problem with iphone 7.  Please fix I keep having to wake up my phone while im driving to hit the next button on my new brand new stereo that is advertised to work with spotify!