I added several local files to spotify via the desktop app. These files are playable through the local files section, but cannot be moved to the songs section to be played in shuffle with other songs. I tried adding the songs to a playlist first, which made them available on my mobile device, but they still could not be added to songs. Dragging the songs from the local files section or playlist section into the songs section does nothing. Downloading them does nothing. Performing any of the aformentioned processes, then restarting the app does nothing.