[Xiaomi Mi A1 ROMs, Kernels, Recoveries, & Other De] osaruchan:
No in-coming call ringtone etc when connected to Bluetooth device

Pardon me if I am posting this to a wrong place etc.

While I am loving this ROM for lots of things, this little issue with Bluetooth has bothered me a lot. I thought I would share this here in hope of getting enlightened by someone here who may have experienced something similar to or the same as the issue I have. This may have been well discussed somewhere before on XDA forum, and if that's the case, someone please point me to the right direction.

Anyway, my Mi A1 connects well to all of my Bluetooth devices (such as headset, car stereo, and portable speaker) and streams media audio fine to these devices and the connection is impressively solid. Even talking to someone on the other end through my BT headset works fine too.

BUT the thing is that I hear NO ringtone for incoming calls from neither the phone nor the connected BT device. Only the way for me to notice an incoming call is to see what's displayed on the screen or to feel/hear the vibration of the phone. Also, I can sometimes tell a call arriving when I am listening to music (media audio) on the BT device, because whatever it is being played would promptly get muted when the phone detects an incoming call and it stays silent until the call is either picked up or timed out.

What makes the matter seem even more complicated is that some system sounds seem to get streamed fine over Bluetooth and some VoIP apps (such as "LINE") even manage to stream incoming ringtone (while some (Skype) don't). Here is the list of behaviors I have observed so far.

• Phone (system app): incoming ringtone CANNOT be heard at all from neither the phone nor the connected BT device.

• Phone (Google's app): incoming ringtone CANNOT be heard at all from neither the phone nor the connected BT device.

• Notification sound (new emails (on Gmail app), new SMS messages, charging etc): CAN be heard from both the phone and the connected BT device - great.

• Alarm, timer (part of the stock clock app) sound: alert/notification CANNOT be heard at all from neither the phone nor the connected BT device.

• Skype: same as the phone apps and new message notification sound CANNOT be heard from neither the phone nor the BT device.

• LINE: incoming ringtone CAN be heard from both the phone and the BT device - Yay!

• Media audio (music, youtube, etc) & caller's voice: all work neatly on all of my BT devices, no issue whatsoever in sound quality etc.

Adjusting the sound volume slider while incoming call is actually arriving would not change anything. Toggling the "Enable In-Band ringing" option (and rebooting thereafter each time) does not seems to change the behavior either. While I feel I have tried many enough suggested "methods", some of which weren't specific to the device or ROM I use, of course, I still have a feeling that there is something I don't know but you guys do might fix the issue.

The behaviors seem to be consistent on all of the 5 different builds of LOS 15.1 I have clean installed from Aug 2018 to Feb 2019.

Some might say I should just go back to stock ROM but I’d really like to explore a bit more for possible fix/workaround before I resort to that.

Thank you guys so much for reading this far. I would greatly appreciate any input you could offer.

*** EDITED ***

PS

By "ringtone", I meant the default built-in ringtone "Orion" and the like - not a custom ringtone or anything like that.

Also, right after posting this, I just noticed that my BT headset emitted a strange tone when the phone was receiving a call and the "Enable In-Band ringing" option was disabled at that time. Maybe it was a built-in ringtone of the headset? But still I'd much like to hear "proper" ringtone from the phone.

Many thanks.