I tried to dig deeper into this issue and used adb logcat in order to better understand what is happening here. I started logging, then I connected the headset and then I recorded a message in Signal. Afterwards I stopped logging.
Grepping all entries for headset / bluetooth / signal I get the results attached.
bt-condensed.txt (242,7 KB)
Here are just the lines containing headset:
07-05 11:37:57.290 2997 3010 I BluetoothAdapterService: getActiveDevices: Headset device: null
07-05 11:37:57.299 2997 3157 I BluetoothAdapterService: getActiveDevices: Headset device: null
07-05 11:37:57.396 2997 3272 I BluetoothHeadsetServiceJni: android/app/jni/com_android_bluetooth_hfp.cpp:92 ConnectionStateCallback: 1 for xx:xx:xx:xx:02:80
07-05 11:37:57.398 2997 3272 I BluetoothHeadsetServiceJni: android/app/jni/com_android_bluetooth_hfp.cpp:92 ConnectionStateCallback: 2 for xx:xx:xx:xx:02:80
07-05 11:37:57.399 2997 3296 I HeadsetStateMachine: Disconnected: currentDevice=XX:XX:XX:XX:02:80, msg=accept incoming connection
07-05 11:37:57.410 2802 2889 D CachedBluetoothDevice: onProfileStateChanged: profile HEADSET, device XX:XX:XX:XX:02:80, newProfileState 1
07-05 11:37:57.413 2997 3157 I BluetoothAdapterService: getActiveDevices: Headset device: null
07-05 11:37:57.414 381 381 D CachedBluetoothDevice: onProfileStateChanged: profile HEADSET, device XX:XX:XX:XX:02:80, newProfileState 1
07-05 11:37:57.416 2997 3353 I BluetoothAdapterService: getActiveDevices: Headset device: null
07-05 11:37:57.510 2997 3157 I BluetoothAdapterService: getActiveDevices: Headset device: null
07-05 11:37:57.526 2997 3353 I BluetoothAdapterService: getActiveDevices: Headset device: null
07-05 11:37:57.537 2997 3296 I HeadsetStateMachine: processAtCind: for device=XX:XX:XX:XX:02:80
07-05 11:37:57.594 2997 3272 I BluetoothHeadsetServiceJni: android/app/jni/com_android_bluetooth_hfp.cpp:92 ConnectionStateCallback: 3 for xx:xx:xx:xx:02:80
07-05 11:37:57.595 2997 3303 I HeadsetPhoneState: stopListenForPhoneState: no listener
07-05 11:37:57.595 2997 3303 I HeadsetPhoneState: startListenForPhoneState: subId=1 events=257
07-05 11:37:57.595 2997 3303 I HeadsetPhoneState: startListener: events=257
07-05 11:37:57.610 2997 3296 E HeadsetSystemInterface: Handsfree phone proxy null for query phone state
07-05 11:37:57.610 2997 3296 I HeadsetService: updateInbandRinging(): Device=XX:XX:XX:XX:02:80 ActiveDevice=null enabled=false connected=true Update all=false
07-05 11:37:57.610 2997 3278 I HeadsetService: setActiveDevice: device=XX:XX:XX:XX:02:80, uid/pid=1002/2997
07-05 11:37:57.623 381 381 D CachedBluetoothDevice: onProfileStateChanged: profile HEADSET, device XX:XX:XX:XX:02:80, newProfileState 2
07-05 11:37:57.624 2997 3278 I HeadsetService: updateInbandRinging(): Device=XX:XX:XX:XX:02:80 ActiveDevice=XX:XX:XX:XX:02:80 enabled=true connected=true Update all=true
07-05 11:37:57.625 2997 3346 I BluetoothAdapterService: getActiveDevices: Headset device: XX:XX:XX:XX:02:80
07-05 11:37:57.628 381 381 D CachedBluetoothDevice: onActiveDeviceChanged: profile HEADSET, device XX:XX:XX:XX:02:80, isActive true
07-05 11:37:57.628 381 381 D CachedBluetoothDevice: onActiveDeviceChanged: profile HEADSET, device XX:XX:XX:XX:7A:0E, isActive false
07-05 11:37:57.628 381 381 D CachedBluetoothDevice: onActiveDeviceChanged: profile HEADSET, device XX:XX:XX:XX:E0:BF, isActive false
07-05 11:37:57.629 381 381 D CachedBluetoothDevice: onActiveDeviceChanged: profile HEADSET, device XX:XX:XX:XX:3A:08, isActive false
07-05 11:37:57.704 2997 3296 I HeadsetStateMachine: processVendorSpecificAt: unsupported command: +TBSF=?
07-05 11:37:57.738 2997 3296 I HeadsetStateMachine: processVendorSpecificAt: unsupported command: +HUAWEIBATTERY=?
07-05 11:37:57.784 2997 3296 I HeadsetStateMachine: processVendorSpecificAt: unsupported command: +XHUAWEISF=?
07-05 11:38:00.061 2802 2889 D CachedBluetoothDevice: onProfileStateChanged: profile HEADSET, device XX:XX:XX:XX:02:80, newProfileState 2
07-05 11:38:00.065 1691 1691 I Telecom : WiredHeadsetManager: ACTION_HEADSET_PLUG event, plugged in: false, : WHC.oADA@m34
07-05 11:38:00.066 2997 3346 I BluetoothAdapterService: getActiveDevices: Headset device: XX:XX:XX:XX:02:80
07-05 11:38:00.067 2802 2889 D CachedBluetoothDevice: onActiveDeviceChanged: profile HEADSET, device XX:XX:XX:XX:02:80, isActive true
07-05 11:38:00.067 2802 2889 D CachedBluetoothDevice: onActiveDeviceChanged: profile HEADSET, device XX:XX:XX:XX:7A:0E, isActive false
07-05 11:38:00.067 2802 2889 D CachedBluetoothDevice: onActiveDeviceChanged: profile HEADSET, device XX:XX:XX:XX:E0:BF, isActive false
07-05 11:38:00.067 2802 2889 D CachedBluetoothDevice: onActiveDeviceChanged: profile HEADSET, device XX:XX:XX:XX:3A:08, isActive false
07-05 11:38:00.192 1691 1691 I Telecom : WiredHeadsetManager: ACTION_HEADSET_PLUG event, plugged in: false, : WHC.oADA@m4E
07-05 11:38:00.197 31612 31685 D APM::HwModule: createDevice: adding dynamic device AUDIO_DEVICE_IN_BLUETOOTH_SCO_HEADSET, @:SUPPRESSED to module primary
07-05 11:38:00.248 1691 1691 I Telecom : WiredHeadsetManager: ACTION_HEADSET_PLUG event, plugged in: false, : WHC.oADA@m4M
I cannot see anything from these log files. Also asking the AI does not really result in a useful answer.
Does anybody have an idea? Would it make sense to raise an issue?