Music library on thumb drive
I copied my old iTunes library to a thumb drive to use on a new MacBook Air (Sonoma 14.3.1). I had no issues syncing with my iPhone 13 until the latest update to iOS 17.4.1. After the update all of my imported music disappeared and only my purchases are available. I went to manually sync music, cabled up and with thumb drive in place, but it is not working. (It is possible that I might have the wrong directory structure on the thumb drive. But that doesn't account for the post-update failure.)
How to resolve?
MacBook Pro 13″, macOS 10.15