This is a problem that I have been watching in all this samsung smartphones (A10,A20,A50,S5 Edge, S7 Edge, S9). I can't exactly say which others but according with what I have been reading about other similar issues I can say it's happening in more that this ones.
I know this is not something from Android since I have been using others from many other brands from Android 8,9,10 and they works as expected.
- Calls turns the entire output audio into mono (I really think just replicating the output might work)
- Calls doesn't allows you to share microphone. It's an issue if you are trying to record a game with in-game call (like Call of Duty)
- Also, coming from the two previous one, usually when in-game call you are not able to have the full 3D audio experience from games.
- All this issues applies for Whatsapp Call & Video, Messenger, Telegram, In-game Calls, Discord, etc...
Note: Like I said. This doesn't happen on other devices. Ex.: Xiaomi Smartphones
Hope to see a solution....
Writing from my Samsung Galaxy S9 (4/64)(Snapdragon 845)
Correction... Changing equalizer settings change the audio as it should, but still all you can hear is Mono.
Notice please that I'm talking about audio while call including non phone call apps like any other voice call feature in any other app, no matter which one.