Samsung Music USED to be my default music player, but as of late, it is not playing mp3 files I had on my SD card in my Note 10. I reformatted the card and reconverted all my music and it still would not recognize all the files on the card.
I tried different music player apps, and I found 2 worked. Musicolet and Oto Music both worked for me. I chose Musicolet as I became used to the UI.
Both apps are in the Play Store.