nostr:npub1xrrt2jpk5j7c0k5hfjd54tte823qh823gmzjfh99qkhrr0kdy5asm9nftg My sister had something similar happen on her new iPhone. Songs that said they'd been downloaded from Apple Music wouldn't play offline. In the end all she needed to do was download one new song and it all started working. Weird.
Apple Music wrecked my library once too and I don't trust it. My ears spend most of their time listing to ripped/purchased music loaded onto the VLC app on my iPhone (the way iTunes used to work), or streaming new mixes with the SoundCloud app.