apple music
i usually update all my playlists on my mac and it saves on my phone, but nothing is syncing to my phone and my playlists on my phone are not updating to what they are on my mac. super annoying..
iPhone XR, iOS 13
Do you have Sync Library enabled on your Mac and iPhone? See the "On your iPhone, iPad, or iPod touch" and "On your Mac" sections in:
Turn on Sync Library with Apple Music - Apple Support