I posted a reply, but it isn't posted, so here goes again?

I had the same issue on my S7. What we're seeing is the new Oreo generic Music controller. You can turn this off - evidently it overrides other media controls. The BP media controls are actually there, just hidden. If you swipe down on any notification you'll see it pop out, along with the quick settings.

To turn it off - Android Settings, Lock screen and security, Clock and FaceWidgets, FaceWidgets. There you'll see toggles for Music controller, Today's schedule, and Next alarm. Once you turn it off the BP controls will reappear.

You don't even need any widget selected, the default notification has ALL the controls.

Skip forward is back!