Apple Music launched a couple of days ago, and one of the service's features is the ability to match and upload songs from your existing personal music library so that you can stream them from anywhere. This feature, also available as a standalone product called 'iTunes Match', unfortunately hasn't been working well for many Apple Music users.
Many people who were already using iTunes Match before switching to Apple Music are reporting that the service has been altering their cloud music libraries without their permission. The most common issues include album artwork being changed, and tracks being moved from their correct albums to completely different albums for seemingly no reason.
Some users have been experiencing more serious issues, such as Apple Music completely deleting their iCloud music library after migrating from iTunes Match to the new music streaming service. Others have seen a few albums deleted from their collection without permission. Both issues are very frustrating for users that have previously experienced no issues with iTunes Match, especially for those without backups of their library.
Apple Music is also reportedly applying DRM to songs matched and uploaded to iCloud, something that iTunes Match never did. This means that if you want to download your previously DRM-free songs that you uploaded to the cloud, you won't be able to listen to them without an Apple Music subscription, as the DRM applied is the same Apple Music uses for offline listening functionality.
New users of Apple Music and its song matching functionality luckily aren't experiencing as many issues, although some people are still having difficulties getting the service to correctly match songs. Considering the service launched just two days ago, Apple can be excused for a few teething problems, but problems with people's existing iTunes Match libraries need to be addressed before more people are affected.