SOLUTION: Duplicate purchased songs on iPhone when syncing with my Mac

I’ve struggled with this issue for a while, but I finally found a workaround. When I sync music imported from CDs to my iPhone, it ends up duplicating songs I’ve already purchased from the iTunes Store.

To prevent this, I created a smart playlist on my Mac using the Music app. This playlist automatically excludes purchased songs and includes only the tracks I’ve imported from CDs.

When syncing your iPhone, make sure to select this specific playlist. That way, only your imported songs will be transferred, no duplicates from your purchased library.