Audio cuts when using the device's Phone UI

[amilcar-uptech]

Hello. I'm not sure if this counts as a bug or a feature request, though I'll try to keep it brief.

I'm using Callkeep to show incoming and outgoing calls for my app on Android. However, I would like to play a sound while an outgoing call is ringing. I tried using AssetsAudioPlayer for this purpose, and while it works when initiating the call, the moment the Phone UI shows up, the audio stops altogether. If I don't manually or programatically stop the audio once the call ends, it will still be playing, as if the device simply silenced the audio and not outright stop it.

Is there a way to keep the audio's volume up all the while? I'm assuming this has something to do with the way the device prioritizes tasks, but I can't say for sure.