manually manage music iTunes 12 and iOS 11.1.1

Having difficulty manually managing music with an iphone 6 and iTunes. None of the songs that I drag onto the device are being added. INSTEAD, ITUNES TRIES TO ADD a random selection of songs. I use Playlists to organize files. When I attempt to drag an entire playlist, it just shows the song list, but does not copy the files.

No settings have been changed. I always back up the full device in iTunes (not iCloud).

I have powered down the device, and rebooted Mac, to no avail. Same situation. Will not allow manual management of music files.

Any advice is appreciated.

iOS 11.1.1

iTunes 12.7.1.14