can't hear a ringtone in Bluetooth headphones

• /e/ version: 1.4
• Device model(s): FP3
• Device rooted: no

Summary

When an event occurs which causes a ringtone to be played I can't hear it in my Bluetooth headphones. Never.

The problem

Steps to reproduce

Connect Bluetooth headphones, good is one with proper Active Noise Cancelling. Then get a call.

What is the current behavior?

The music (or what you currently have in your headphones) is faded out. Then the ringtone is played in the speaker of the phone. If the ringtone belongs to a call it will also be repeated until the caller hangs up. When all is over the music is faded in again.

Great. It took me really a while until I noticed with my noise cancelling headphones on that I have a call (happens not very often). Music was faded out - why??? And what do you do then? What is natural human behavior now? You take the headphone off! Of course you do. Ah, there's a ringtone, sounds like a call. Now you take the call but you will again not hear something. Why? Because the other one is in the damned headphones!

Update: It seems that configured message notification tones (SMS, email, messenger) get into the Bluetooth headphones. At least the ringtone from an incoming call does not.

Update /e/ 2.2: No, the notification sounds do not get into the Bluetooth headphones. The volume in the headphones is reduced, then it beeps outside the headphones and then the volume in the headphones is raised again. It's ridiculous.

What is the expected correct behavior?

When the user would get the ringtone in the headphone it would be absolutely normal that he could also react with headphones on.