Phone stops sending audio to Bluetooth and starts playing over speaker.

[Android Central Question]

I have a Moto G4 XT1625 on 7.0 with 4/1/18 security patches.

Last Sunday, it started doing this awful thing where it'll stop playing audio through the Bluetooth and start playing it through the speaker. Sometimes it's after a minute, sometimes it's after twenty. To be clear, the Bluetooth doesn't disconnect. The radio and the status icon on the phone both indicate they're still connected.

I've tried:
Rebooting
Clearing data in Bluetooth share
Deleting the car from the phone and the phone from the car and repairing
Rolling Carrier Services back to the version that shipped with the phone (it updated right before this started)
Uninstalling Android Auto

This problem isn't limited to one app. It's happened in Google Play Music, Amazon Music, and iHeartRadio. Both stand alone and inside Android Auto.

Thoughts? Is anyone else seeing this?

 

[Laura Knotek]

Welcome to Android Central.

Have you checked with the car dealership to see if there is any new firmware for the car's head unit?

 

[Wordster]

This exact thing started happening to me this week on two separate cars. No way this is a car firmware issue. I bluetoothed with both cars for years and my phone for several months. I feel like this is an android update issue. I have a galaxy s9+.

 

[Laura Knotek]

This exact thing started happening to me this week on two separate cars. No way this is a car firmware issue. I bluetoothed with both cars for years and my phone for several months. I feel like this is an android update issue. I have a galaxy s9+.

The car's head unit might need a firmware update due to the Android update. It's possible that the car's head unit isn't compatible with the latest version of Android. Since the car is older than the phone OS, its head unit firmware was designed for use with an older version of Android.