I see, well, thanks for the response. I've a feeling it could be an error with Microsoft's OS for the Xbox One. Sometimes, system updates can introduce strange issues. Here's hoping someone can join in and that MS takes notice.

No feedback at all? Just great... ! :)

There's an issue with the Dolby Access app on Xbox One - it allows you to use the DA w/headphones setting only once. If you shutdown or restart your console, the app defaults to Windows Sonic and will not allow you to select DA. For now, I've found a workaround - uninstall, redownload and...