[MTCD Android Head Units General] bzzzzzz:
I'm having some issues connecting my Honor 6 (H60-L04 EMUI 4.0 Marshmallow 6.0) via bluetooth with my new Hizpo PX5 4GB ( MTCE_CZ_V3.02b_1 ) with Android 8.0.

The pairing went fine, the audio call sharing and the multimedia audio are enabled on the phone, I can stream music via AD2P through the car's speakers and download the address book in the HU's bluetooth phone app.

I can also start a call from the HU, the phone compose the number but then it does not show the bluetooth speaker option, so it uses its own microphone and internal speaker. If I hang the call from the HU, the phone hangs the call immediately but the HU remains in a waiting state (the hang button remains locked for 10 seconds); also, if someone call me on the phone, the HU doesn't notice it.

I'm not really sure where the problem is, because:

the phone works with any other bluetooth speakerphone

the phone works with the stock car stereo (Toyota TNS350)

the HU's bluetooth works correctly with other phones (I've tried with a Honor 7s Android 8.1, the call is routed on the HU)

sometimes (very rare...) it worked also with my phone, once also for an entire day!

in the exact moment I see the issue with my phone, another paired phone works well

the HU has an external bluetooth/wifi antenna, placed directly beneath the phone

I've tried to:

unpair the phone from the HU, unpair the HU from the phone, and reboot both of them

change the bluetooth chipset from the HU factory settings (the original was WQ_BC6), I've tried all of them

flash Malaysk and Hal9K Android 8.0, same results as stock rom

disable the wifi on the HU

Here the logs on the HU when starting and then hanging the call, I can see some "AT: result[51] Data[7][ERROR" (now I'm on Hal9K 3.1.1 rom):

D/AndroidRuntime(19638): >>>>>> START com.android.internal.os.RuntimeInit uid 0 <<<<<<
D/AndroidRuntime(19638): Calling main entry com.android.commands.am.Am
D/AndroidRuntime(19638): Shutting down VM
D/SurfaceFlinger( 289): duplicate layer name: changing Toast to Toast#1
E/ActivityManager( 552): getPackageFerformanceMode--ComponentInfo{com.microntek.bluetooth/com.microntek.bluetooth.MainActivity}----com.microntek.bluetooth
E/ActivityManager( 552): getPackageFerformanceMode--ComponentInfo{com.microntek.bluetooth/com.microntek.bluetooth.MainActivity}----com.microntek.bluetooth
I/wuwq (19650): BlueToothActivity onCreate cfg_bt=3
D/OpenGLRenderer(19650): HWUI GL Pipeline
I/BlueToothService( 552): serviceWriteCommand: AT-MX
D/goc (14433): command:AT-MX
D/goc (14433): ON_INQUIRY_PAIR_RECORD
D/goc (14433): pbap_getPairList 1
D/goc (14433): config_read key:name0 value:H60-L04
D/goc (14433): config_read key:addr0 value:241FA05CDCFB
E/goc (14433): PairList[0] : 241FA05CDCFB H60-L04
D/goc (14433): ---GOCSDK_PAIRSTATUS cod:5a020c classtype: 2
D/goc (14433): send_ind: [JI12241FA05CDCFBH60-L04]
E/goc (14433): read record from file error
D/goc (14433): ---GOCSDK_PAIRSTATUS cod:ffffffff classtype: 2
D/goc (14433): PairList is Over
D/goc (14433): send_ind: [JY]
D/goc (14433): send_ind: [OK]
I/BlueToothService( 552): BC6 BT read:
I/BlueToothService( 552): BC6 BT read: JI12241FA05CDCFBH60-L04
I/BlueToothService( 552): BC6 BT read:
I/BlueToothService( 552): BC6 BT read: JY
I/BlueToothService( 552): BC6 BT read:
I/BlueToothService( 552): BC6 BT read: OK
I/OpenGLRenderer(19650): Initialized EGL, version 1.4
D/OpenGLRenderer(19650): Swap behavior 2
D/SurfaceFlinger( 289): Backpressure trigger, skipping transaction & refresh!
I/ActivityManager( 552): Displayed com.microntek.bluetooth/.MainActivity: +518ms
I/BlueToothService( 552): serviceWriteCommand: AT-VB
I/BlueToothService( 552): ============= + musicUnmute + =================
D/goc (14433): command:AT-VB
D/goc (14433): ON_MUSIC_UNMUTE
D/goc (14433): a2dp_player_setvol :val:1.000000
D/goc (14433): a2dp_player_setvol volume to 1.000000
D/goc (14433): send_ind: [OK]
I/BlueToothService( 552): BC6 BT read:
I/BlueToothService( 552): BC6 BT read: OK
--------- beginning of system
W/ContextImpl( 552): Calling a method in the system process without a qualified user: android.app.ContextImpl.sendBroadcast:950 android.content.ContextWrapper.sendBroadcast:431 android.microntek.service.MicrontekServer.p:600 android.microntek.service.MicrontekServer.am:174 android.microntek.service.MicrontekServer.be:0
W/WindowManager( 552): removeWindowToken: Attempted to remove non-existing token: android.os.Binder@48f0fe1
D/SurfaceFlinger( 289): Backpressure trigger, skipping transaction & refresh!
W/ContextImpl( 552): Calling a method in the system process without a qualified user: android.app.ContextImpl.sendBroadcast:950 android.content.ContextWrapper.sendBroadcast:431 android.microntek.service.MicrontekServer.p:600 android.microntek.service.MicrontekServer.am:174 android.microntek.service.MicrontekServer.be:0
I/BlueToothService( 552): serviceWriteCommand: AT-CZ190
D/goc (14433): command:AT-CZ190
D/goc (14433): ON_DIAL: 190
D/goc (14433): send_ind: [OK]
D/goc (14433): GOC_Phone_Dail number(190)
D/goc (14433): at_send_cmd:ATD190;
I/BlueToothService( 552): BC6 BT read:
E/goc (14433): send_calling
I/BlueToothService( 552): BC6 BT read: OK
E/goc (14433): send_current_number:190
D/goc (14433): callback_talk_status number(190)
D/goc (14433): >:ATD190;
D/goc (14433): on hfpstatus:190,1
E/goc (14433): auth:1
E/goc (14433): config_read key:autoanswer not found
D/goc (14433): autoanswer :0
D/goc (14433): send_ind: [MF10]
D/goc (14433): send_ind: [S43]
E/goc (14433): do_send_calling:190
D/goc (14433): send_ind: [IC03190]
I/BlueToothService( 552): BC6 BT read:
I/BlueToothService( 552): BC6 BT read: MF10
I/BlueToothService( 552): BC6 BT read:
I/BlueToothService( 552): BC6 BT read: S43
I/BlueToothService( 552): BC6 BT read:
I/BlueToothService( 552): BC6 BT read: IC03190
I/wuwq ( 552): query number:190, bMachineNumber:false
I/BlueToothService( 552): serviceWriteCommand: AT-VB
I/BlueToothService( 552): ============= + musicUnmute + =================
D/goc (14433): command:AT-VB
D/goc (14433): ON_MUSIC_UNMUTE
D/goc (14433): a2dp_player_setvol :val:1.000000
D/goc (14433): a2dp_player_setvol volume to 1.000000
D/goc (14433): send_ind: [OK]
I/BlueToothService( 552): BC6 BT read:
I/BlueToothService( 552): BC6 BT read: OK
D/goc (14433): <:
D/goc (14433): +CIEV: 4,5
D/goc (14433): handle_hf_CievInd: signal = 5
D/goc (14433): --------->signal :5
D/goc (14433): at_send_cmd:ATD190;
D/goc (14433): hfp_qurey_DailTimeOut 3s, So Send ATCmd(ATD190;)
I/BlueToothService( 552): serviceWriteCommand: AT-CG
D/goc (14433): command:AT-CG
D/goc (14433): ON_FINISH_PHONE
D/goc (14433): GOC_Voice_Dail GOC_Voice_Dail : -1255219949
D/goc (14433): >:AT+BVRA=0
D/goc (14433): at_send_cmd:AT+BVRA=0
E/goc (14433): auth:1
E/goc (14433): hungup_query_delay: times = 10
D/goc (14433): phone_ringstop
D/goc (14433): send_ind: [VR0]
D/goc (14433): ring_stop
D/goc (14433): GOC_Phone_HungUp
D/goc (14433): send_ind: [OK]
D/goc (14433): >:AT+CHUP
E/goc (14433): auth:1
I/BlueToothService( 552): BC6 BT read:
I/BlueToothService( 552): BC6 BT read: VR0
I/BlueToothService( 552): BC6 BT read:
I/BlueToothService( 552): BC6 BT read: OK
D/goc (14433): <:
D/goc (14433): OK
D/goc (14433): <:
D/goc (14433): ERROR
D/goc (14433): AT: result[51] Data[7][ERROR
D/goc (14433): ]
D/goc (14433): >:ATD190;
E/goc (14433): auth:1
D/goc (14433): <:
D/goc (14433): ERROR
D/goc (14433): AT: result[51] Data[7][ERROR
D/goc (14433): ]
D/goc (14433): >:AT+BVRA=0
E/goc (14433): auth:1
D/goc (14433): <:
D/goc (14433): ERROR
D/goc (14433): AT: result[51] Data[7][ERROR
D/goc (14433): ]
I/Finsky (15209): [124] iea.run(3): Stats for Executor: BlockingExecutor ifl@e541762[Running, pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 12]
I/Finsky (15209): [124] iea.run(3): Stats for Executor: LightweightExecutor ifl@ba00f3[Running, pool size = 4, active threads = 0, queued tasks = 0, completed tasks = 61]
I/Finsky (15209): [124] iea.run(3): Stats for Executor: bgExecutor ifl@a6ea1b0[Running, pool size = 4, active threads = 0, queued tasks = 0, completed tasks = 45]
E/memtrack( 552): Couldn't load memtrack module
W/android.os.Debug( 552): failed to get memory consumption info: -1
I/chatty ( 552): uid=1000 system_server identical 5 lines
W/ContextImpl( 552): Calling a method in the system process without a qualified user: android.app.ContextImpl.sendBroadcast:950 android.content.ContextWrapper.sendBroadcast:431 android.microntek.service.MicrontekServer.p:600 android.microntek.service.MicrontekServer.am:174 android.microntek.service.MicrontekServer.be:0
I/ActivityManager( 552): START u0 {flg=0x10804000 cmp=com.android.systemui/.recents.RecentsActivity} from uid 10025
E/ActivityManager( 552): getPackageFerformanceMode--ComponentInfo{com.android.systemui/com.android.systemui.recents.RecentsActivity}----com.android.systemui
E/BufferItemConsumer(10429): [unnamed-10429-8] Failed to release buffer: Unknown error -1 (1)
D/SurfaceFlinger( 289): Backpressure trigger, skipping transaction & refresh!
W/ContextImpl( 552): Calling a method in the system process without a qualified user: android.app.ContextImpl.sendBroadcast:950 android.content.ContextWrapper.sendBroadcast:431 android.microntek.service.MicrontekServer.p:600 android.microntek.service.MicrontekServer.am:174 android.microntek.service.MicrontekServer.be:0
E/BufferItemConsumer(10429): [unnamed-10429-9] Failed to release buffer: Unknown error -1 (1)
W/zygote64(10429): Checksum mismatch for dex SystemUI.apk
W/zygote64(10429): Checksum mismatch for dex SystemUI.apk
E/IMGSRV (16865): clear.c:2632: alpha is NOT supported, to set it to 1, original value : 1.000000
I/chatty (16865): uid=10091(u0_a91) com.android.noisefield identical 1 line
E/IMGSRV (16865): clear.c:2632: alpha is NOT supported, to set it to 1, original value : 1.000000
I/zygote64(10429): Deoptimizing void com.android.systemui.statusbar.notification.NotificationHeaderViewWrapper.onContentUpdated(com.android.systemui.statusbar.ExpandableNotificationRow) due to JIT same target
E/IMGSRV (16865): clear.c:2632: alpha is NOT supported, to set it to 1, original value : 1.000000
E/ActivityManager( 552): Sending non-protected broadcast ru.hal9k.info from system 10429:com.android.systemui/u0a25 pkg com.android.systemui
E/ActivityManager( 552): java.lang.Throwable
E/ActivityManager( 552): at com.android.server.am.ActivityManagerService.checkBroadcastFromSystem(ActivityManagerService.java:19183)
E/ActivityManager( 552): at com.android.server.am.ActivityManagerService.broadcastIntentLocked(ActivityManagerService.java:19799)
E/ActivityManager( 552): at com.android.server.am.ActivityManagerService.broadcastIntent(ActivityManagerService.java:19941)
E/ActivityManager( 552): at android.app.IActivityManager$Stub.onTransact(IActivityManager.java:240)
E/ActivityManager( 552): at com.android.server.am.ActivityManagerService.onTransact(ActivityManagerService.java:3020)
E/ActivityManager( 552): at android.os.Binder.execTransact(Binder.java:674)
W/BroadcastQueue( 552): Background execution not allowed: receiving Intent { act=android.intent.action.DROPBOX_ENTRY_ADDED flg=0x10 (has extras) } to com.google.android.gms/.stats.service.DropBoxEntryAddedReceiver
W/BroadcastQueue( 552): Background execution not allowed: receiving Intent { act=android.intent.action.DROPBOX_ENTRY_ADDED flg=0x10 (has extras) } to com.google.android.gms/.chimera.GmsIntentOperationService$PersistentTrustedReceiver
E/IMGSRV (16865): clear.c:2632: alpha is NOT supported, to set it to 1, original value : 1.000000
I/zygote64( 552): Background concurrent copying GC freed 83433(4MB) AllocSpace objects, 20(592KB) LOS objects, 42% free, 16MB/29MB, paused 925us total 267.959ms
E/IMGSRV (16865): clear.c:2632: alpha is NOT supported, to set it to 1, original value : 1.000000
I/zygote64( 5357): Background concurrent copying GC freed 62154(2MB) AllocSpace objects, 10(200KB) LOS objects, 49% free, 10MB/20MB, paused 460us total 150.682ms
E/IMGSRV (16865): clear.c:2632: alpha is NOT supported, to set it to 1, original value : 1.000000
I/chatty (16865): uid=10091(u0_a91) com.android.noisefield identical 8 lines
E/IMGSRV (16865): clear.c:2632: alpha is NOT supported, to set it to 1, original value : 1.000000
I/BlueToothService( 552): serviceWriteCommand: AT-VB
I/BlueToothService( 552): ============= + musicUnmute + =================
D/goc (14433): command:AT-VB
D/goc (14433): ON_MUSIC_UNMUTE
D/goc (14433): a2dp_player_setvol :val:1.000000
D/goc (14433): a2dp_player_setvol volume to 1.000000
D/goc (14433): send_ind: [OK]
E/IMGSRV (16865): clear.c:2632: alpha is NOT supported, to set it to 1, original value : 1.000000
I/BlueToothService( 552): BC6 BT read:
I/BlueToothService( 552): BC6 BT read: OK
E/ActivityManager( 552): getPackageFerformanceMode--ComponentInfo{rs.pedjaapps.alogcatroot.app/rs.pedjaapps.alogcatroot.app.LogActivity}----rs.pedjaapps.alogcatroot.app
E/IMGSRV (16865): clear.c:2632: alpha is NOT supported, to set it to 1, original value : 1.000000
E/BufferItemConsumer(10429): [unnamed-10429-10] Failed to release buffer: Unknown error -1 (1)
E/ActivityManager( 552): getPackageFerformanceMode--ComponentInfo{rs.pedjaapps.alogcatroot.app/rs.pedjaapps.alogcatroot.app.LogActivity}----rs.pedjaapps.alogcatroot.app
W/ContextImpl( 552): Calling a method in the system process without a qualified user: android.app.ContextImpl.sendBroadcast:950 android.content.ContextWrapper.sendBroadcast:431 android.microntek.service.MicrontekServer.p:600 android.microntek.service.MicrontekServer.am:174 android.microntek.service.MicrontekServer.be:0
E/BufferItemConsumer(10429): [unnamed-10429-11] Failed to release buffer: Unknown error -1 (1)
I/chatty (16865): uid=10091(u0_a91) com.android.noisefield identical 1 line
E/IMGSRV (16865): clear.c:2632: alpha is NOT supported, to set it to 1, original value : 1.000000

Maybe is a connection strenght problem? Maybe my phone has a weak bluetooth signal and in conjunction with the poor bluetooth chip quality of the HU, it generates this issue?

Or an issue on Android 6.0 connecting to a 8.0 ?

I would like to try with an external bluetooth USB dongle, but it seems not so easy to find a dongle with a supported chipset (on another thread I've found the Comfast CF-WU725B would work, but only if it's type 1 because type 2 it's not supported anymore on Android 8.0 ...).

The very last chance is to change my phone, but I really would like to avoid :)