Note: I believe this may be the same problem this user was seeing.
Sometimes (not always, but often) when my doorbell alerts and I use my Android phone to go to the Home app to see the doorbell video, it breaks Bluetooth play/pause from my Bluetooth devices. Typical scenario: I'm listening to an audiobook on a Bluetooth speaker or headphones connected to my Android phone, using the Audible app. The doorbell alerts. I switch to the Home app and look at the doorbell video. This causes the Bluetooth speaker to play audio from the doorbell video.
When I'm done reviewing the doorbell video, I switch back to the Audible app. From this point on, the play/pause button on my Bluetooth speaker/headphones/whatever no longer functions correctly. When I press the play/pause button on the Bluetooth speaker to pause playback, the playback stops very briefly (1-2 seconds), then simply continues playing. If I watch the Audible app while I press the speaker's pause button, where I'd normally see the play indicator in the app switch to pause, nothing happens in the app.
If I use the app to pause playback, then press the speaker's play/pause button, again nothing happens. Playback does not resume.
This is not limited to the Audible app. Any app that streams to a Bluetooth device has the same problem. If I am experiencing the problem and switch to a different app to stream to my Bluetooth device, the Bluetooth device cannot play/pause the playback from that app either. Restarting the app does not fix the problem. Restarting the Bluetooth device does not fix the problem. This is true no matter which order I restart the Bluetooth device and the app.
Turning Bluetooth off on the phone, then turning it back on and connecting to the Bluetooth device also does not fix the problem.
Disconnecting from the current Bluetooth device and connecting to a different Bluetooth device also has no effect; the new device's play/pause button also does not work. The only fix for this problem is to restart my phone. I cannot begin to tell you how annoying this is. I listen to audiobooks (or music) constantly, and I get a lot of doorbell alerts. I'm forced to restart my phone multiple times a day. This has been going on for months, probably for more than a year.
And that's not all. When this problem occurs, the volume of the playback is much lower than usual. If I crank the volume on my phone to max and crank the volume on the Bluetooth device to its max, a move that would normally result in a volume so loud as to cause my ears to bleed, the volume actually coming out of the Bluetooth device is very moderate. The volume up/down buttons on the Bluetooth device do still work, but the maximum volume attainable is far lower than normal. Again, restarting my phone fixes this.
