My device suddenly deleted all my downloaded music, everything I had. Then when I tried downloading again it set the storage to the internal space, I changed it to the SD card so I can have more space on the phone.
It started downloading normally but then got the notification that I was running low on space, the phone took back the storage to the internal space and went let me change it back to the SD card.
The option to switch back the storage format even appear on the configuration options anymore.
The link you provided does not exist, can you please provide us with another solution because no matter what I do I cannot get Spotify to detect my perfectly-working-with-everything-else-on-my-device SD card or allow me to move my music to it. I cannot believe it is 2020 and we don't just have a streamlined option to move Spotify to the SD card when everyone knows internal storage is minuscule and music files are huge.