Some users have said that enabling / disabling the iCloud Music Library will cause them to start syncing and force an update to albums on their iPhone, but this can cause more issues such as deleted music and removal of some music downloads. Fortunately, a user on the Apple Support Communities Web site shared a helpful temporary fix for the issue, which successfully completed MacRumor's more than five times.
To manually update your iPhone's music library, simply create a new, empty playlist by tapping the Library tab in the iOS Music app , Tap New Playlist and tap Done. Once the update is complete, skip to the bottom of the playlist page and 3D Touch to clear the empty playlist. Note that it also updates and adds songs that have been added or removed from playlists.
There is no solution, but there is a solution until Apple fixes it: Just create an empty playlist on the iOS device. This forces a read / write to the library stored in iCloud. Then all your changes will be deleted suddenly. You have to do this every time, it's essentially a manual update.
Unfortunately, the reverse method in iTunes on Mac does not seem to work so consistently, but desktop users also have another possible simple solution to update their library: just rate a song by liking / disliking it , Then, the Recently Added tab in iTunes should be updated to add or remove content you created on other devices connected to the same iCloud account.
On both macOS and iOS, you can also add another new song, album, or playlist to your library to manually update and force content that is not synced across devices. Then you can delete the new songs after everything else has been updated.
Several Apple Music subscribers have opened support cases for the bug, and Apple support has indicated in most cases that it's not a known issue. Support staff, however, said to a user that they will start an investigation after "rebooting, changing the password, logging out of iCloud and turning off the iCloud music library" and more.
SOURCES: TECHCRUNCH.COM GSMARENA.COM MACRUMORS.COM FIRSTPOST.COM ANDROIDCENTRAL.COM PHANDROID.COM TECHSPOT.COM
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