The "in call volume" issue
I found that if I'm on a call using messenger app sometimes it messes up an wont let me talk using bluetooth which causes my phones volume to say in call volume as if I'm still on the call. An it wont let me play sound on headset when on snapchat or Facebook videos it plays thru phone speaker.
Fixed it by uninstalling messenger now I will reinstall an see if it still keeps doin it. Both bluetooth devices it did it too. So it isnt headset but it's the app.