Now I encountered an issue.
IF the Music on PC is stored in several folders, we used always Media Player to copy music to the smartphone.
This way we did not need to dive into all folders to look for it, as Media Player listed us the titles from all folders.
Why don't you allow syncing tracks in Groove with W10 Mobile or other portable players, as we had with WMP?
It's an important feature, not everyone has the Music in the Cloud.