Mi11 Ultra Android Auto phone call sound via car speaker

[panamenra]

Hi guys,
I have Mi11 Ultra with the latest Weekly ROM - 21.9.1 (but the issue is valid also for the previous ones). It can connect to the car Android Auto with USB cable and everything look to work fine except that when I receive a phone call the sound goes only via the phone but not through the car speakers. I have tried all recommendations that can be found in internet without success. If I use Bluetooth only (no cable and thus no android auto) then phone call voice goes via car speakers.
I plan to get back to the original Xiaomi ROM for EU and to test again but meanwhile can someone share if they have seen such behavior. Maybe it doesn't work only for me - could be the car or something.
With Huawei P30 pro it works perfectly fine. Just for reference as it is not the same case but it also works with iPhones (not android auto).
Many thanks in advance for every reply!

 

[Karpfenhai]

Can't confirm, works flawless on different cars, all younger than 5 years.

Try a different cable, I had once one which worked only in a certain direction, even with usb-c.

Regards

Sent from my Mi 11 Ultra.

 

[panamenra]

Thank you Karpfenhai! Anyway I spent some time to revert back to the initial official ROM - RKAEU and with this ROM AA works fine - voice during phone calls goes via car speakers. My best guess is that EU rom comes from china one where AA is not available thus it is added later when producing the EU and there something is not good at least for me.
Most probably I will do some more testing with more ROMs when I have time.

 

[panamenra]

Solved.
Issue is found and here it is (admin/moderator can lock the theme and may be put Solved in the title):
I have Huawei Watch GT2 pro. If I pair the watch and enable all permissions (which must be done anyway or the watch will not sync or not show all data, etc) then I lose the voice for calls via car speakers. I tested this on official and on Weekly ROMs and it's the same.
Good news is that there is a simple solution - disable phone calls from Bluetooth setting for the watch.
Unfortunately there is not full happiness so if I do that and watch disconnects from phone (because of high distance for example) then it doesn't auto reconnect. This look to be a "nice" feature from Huawei, here their official statement:
"3. For devices that support Bluetooth calling, if you manually turn off the audio call switch in the Bluetooth settings of your phone (with the exception of devices with an audio call switch that is turned off by default), your phone will fail to reconnect to your device via Bluetooth after disconnecting."
Note that Huawei phones doesn't have this problem maybe because they work better with their own watches.