[Zubersoft]

Do you have any other applications running on the device that utilize WASAPI? It's possible the other application is taking exclusive control over the audio output through WASAPI which means MobileSheets won't have access to it. If that's not the issue, look at the Volume Mixer in Windows 10 and verify that MobileSheets is going out through the audio device that you are expecting it to. Have you rebooted your device yet to ensure it's not a weird issue that might be resolved with the audio driver being reset?

Mike