Time machine not backing up all music
I have a 2021 MacBook M1 Pro running the latest Ventura OS. Time machine hooked up to two mirrored backup drives. In iTunes I have many examples of an album not being backed up on either drive, even though other albums by the same artist are backed up just fine. I have excluded nothing from the backup menu in Time Machine. What do I do now?
MacBook Pro 14″, macOS 13.4