So, my galaxy s8+ showed up as two different devices under preferences, one for the internal storage and one for the SD card, but both were given the exact same name. I deleted what I thought was the internal storage because I never wanted to sync music there. Turns out I deleted the SD card one instead, as when I went to sync a large playlist, it filled up my internal storage, and didn't have enough room for everything. How do I get musicbee to recognize my phone's SD card again?