How to investigate/report mobile phone call bug

[StephenG1CMZ]

I'd appreciate any tips on how to discover what's wrong with my mobile and/or any tips on how to report the bug, which prevents calls (possibly including 911 calls TBC)..

I am using the mobile as my principal device for voice calls, Internet access and HP Prime emulation, so a factory reset would be disappointing, and rooting the device/sending it for repair/using a paid-for developers SDK impractical.

Background: I rarely do this, so I am not sure if this is a longstanding issue, or an update causing a fault today.

What happened today:
I tried to call 2345 to check my mobile balance (using normal touch dial) . The call seemed to hang up immediately (within a second or 2) and then started playing music. I also saw that Google Assistant was triggering on the screen.
Investigation revealed that:.
Dialled and Contact calls fail.
As I don't want to risk a 911 hangup, I cannot confirm 911 calls are affected but cannot trust the device (actually, its 999 or 112 here).
Incoming calls fail.
The culprit music app is Huawei Music Player (force stopping ceases playback).
The culprit music app is a system app and cannot be uninstalled.
And on demonstrating the fault to someone:
Unplugging the headphone allows calls to be made!!!
It works with a different headphone (I haven't yet retested the original headphone).
I'd be interested in any hints from the helpful folks here on the following points:
Technical:
How can I discover what is triggering the fault? I know its the headphone socket/headphone, but what is activating the Google Assistant and Huawei Music Player? Actually, it looks like it is a specific headphone (or the fault has been fixed remotely) - but why would one headphone trigger Hangup/Play Music, and another headphone not?
How can I test 911 calls without risking a hangup?
Is there a similar test number with the same phone behaviour but without the potential annoyance?
When I used to test BT landlines I was isolated, so I could test 911/credit card interaction without worrying about the dispatcher.
Bug reporting:
Where should the fault be reported ?
Huawei? (the phone manufacturer and supplier of the culprit music app)
Google Assistant?
Ofcom/FCC?

[David Hayden]

Power-cycle the phone. I had a similar problem (different phone manufacturer though) and a power cycle fixed it.

Try the suspect headset in a different phone. If the problem follows the headset then you've found your culprit.

If the headset plugs into the phone, clean the contacts with compressed air.

Good luck!
Dave

[ijabbott]

If you go to "Settings" and search for "Phone app", is it set to the system default Phone application? Does that change if you plug in the suspect headset?

Can you disable the Huawai Music app, even if you can't uninstall it?


<rant>I hate bloatware on phones that you can't uninstall, so I ditch the manufacturer's OS and replace it with something like LineageOS. However, I think Huawai prevent you doing that on a lot of their phones by not allowing the bootloader to be unlocked.</rant>

[cdmackay]

Try finding the settings for "default" apps, and clear whatever might be set for music, or any default app settings associated with the culprit app.

I can't suggest where those settings might be, sorry; I find it hard enough on my Samsung.

[StephenG1CMZ]

It has been suggested elsewhere that a press on the mic key is designed to play music or trigger Google Assistant, something I was unaware of.
So the fact that the Huawei seemed like it was prioritising music playback over making calls and playing music unexpectedly is no longer mysterious.
It can all be explained by a dodgy mic lead - which I would have considered had it just been hanging up.

Who would have guessed that pressing the mic key would play music rather than record sound?