Music Player not syncing

[Hoje0308]

The first time I add music, it it will all show up in the Music Player. Subsequent additions to the phone do not show up in the Music Player, however. I've tried dropping the music files in different folders, with no luck, as well as just dropping it in the hard drive folder. The only way to find them is to go to the Files application. Another weird thing is that the music seems to show up if I do a factory reset. Anyone know what is going on here? Also, music and video that I put on the SD card do not show up anywhere except the aforementioned Files app.