Clip Zip not recognizing Genres

Just loaded some MP3 music onto the SD memory of my Clip Zip by drag-and-drop-ing from my PC with Windows Explorer. The songs play as expected but are not listed in the Zip Clip by Genre despite the fact that their genres (e.g. Country, Blues) are listed under file Properties in Windows Explorer and also appear in MediaMonkey. Can anyone here tell me the possible cause and how to correct it ?

Update: a few hours later the Clip Zip is now recognizing the genres without my having changed any of the settings or content. During those few hours I plugged and unplugged the Clip Zip’s USB connection to the computer a couple of times. Maybe that caused the Clip Zip to recognize the genres. Puzzling.