I have about four thousand audio files in Music. They are all either mp3 or .m4a, roughly half of each.
Occasionally, I remove all from the iPhone for two reasons:
- I need the space to do an update
- If I edit a song, or add artwork, or change the metadata, sync fails to update the phone.
Today, I removed them all, updated to IOS 14.8, and then put the songs back. Finder complained that nine songs were "not copied because the audio format is not supported by the iPhone."
I knew that those songs had played before. I looked at one of them in Finder, and it is .mp3 I then found it on the iPhone, meaning it was copied. And tapped it, and it did play.
What's going on here?