Solved Surface Book Built-in Speakers Good, But Headphone Problems

[sharpuser]

Yes I see the device. Levels modulate only during the "Test".

 

[sharpuser]

Solved!

Who would have thought that the built-in "Troubleshoot..." option would work so well.

I went through the "Troubleshoot sound problems", which asked me to plug headphones in, unplug, wait, Reconfiguring driver... , and Voila!
All sounds and configurations work perfectly, including Surface Dock speakers.

Thanks, all, including @GoodBytes, but especially, thanks Windows 10.

 

[GoodBytes]

You should thank Windows 7 for putting that feature
Reboot your system and see if it is really solved.