Plan: Premium Mini

Country: India

Device: Tested on Motorola One Power (Android 10), Samsung M21 (Android 11) 

Operating System: Tested with Windows, Mac and Ubuntu

My Question or Issue

I have added local MP3 files to Spotify app in my computer (legal files: I make songs as a hobby. I also tried syncing the royalty free MP3s from YouTube studio)

I want listen to sync these songs in my Android device. The Spotify playlist that I create with my Computer is readily shown on my mobile device. But inside the playlist, all the songs are greyed out. If I try to play it, the progress bar starts at the bottom, but it crashes. If I try to download the song, I get a message "Couldn't download song".

I did try looking at previously provided help, but didn't work for me