Each time I try to send a song to my Samsung, I wait, and it sends. But the tracks are not showing up on my phone. I have tried MM4 and MM5. I have rebooted several times. I have tried different USB cables and ports. I have used MM for a long time and changed nothing on my PC. Even if I search the Samsung with File Explorer, the new tracks never appear.

Do you have any advice on how I can fix this?