During Snapchat and Audio Calls, system volume is overrode by Call Volume

I occasionally watch videos on my phone during calls. Maybe my friend will send me a trailer to watch while I’m talking to them. However, I can’t even hear it above the audio of the call. It’s like what Skype used to do when you would call someone. It’s almost as if Snapchat and the Phone app (likely even FaceTime too) have a code that overrides background audio to favor the call volume. I know this isn’t just related to me as this has been an ongoing problem…has anybody found a solution? Or has there been an update that has fixed this.

also, turning the volume up on my phone while turning up the background volume also turns up the call volume; and the call volume still overrides the background audio. So if the call is loud, it not only hurts my ears but I still won’t be able to hear the video I’m watching (does the same to all music and other sounds)