In addition to some of the issues mentioned by others, the most important problem that I’m facing since iOS 18 is that the currently playing list is lost when connected to external devices (car, in my case) through USB. When starting to play a list, the songs in the currently playing list appear properly and so does the number of the song. After a while, usually when moving to the next song, the song’s number appears as 1, and the list is no longer accessed from my car's interface (latest Mercedes in my case) and therefore I can no longer move to next/previous song. I’m forced to switch to Bluetooth so I can move to another track, but I naturally prefer the USB as it used to provide better manipulation and quality.
Interestingly enough, the same occurs even if I switch to CarPlay! Of course in that case I can access the list through CarPlay’s interface, but in the car's dashboard the list is still lost and I can still not move through songs.
I’m having a premium Apple Music subscription and the latest updates rendered my iPhone almost unusable in one of its most important usages (since I’m traveling a lot).
I do not know if the same happens with other streaming applications (I only maintain this subscription), but I suspect this is an issue of the iOS and not of Apple Music in particular. It appears to be an issue with the iTunes Library API the iPhone is using to expose media players’ content to external devices. If I use the Apple Music app from an Android device, I don’t have this issue!
Needless to mention the issue we always had and it’s been posted tens of times: That when we reconnect to the car, what was being played is always lost and the phone switches to playing the first song from the All Songs, alphabetically. That was there always and I had to make an automation to switch back to a preferred list, which is still not a solution.
So, while for others this may seem a reason to abandon Apple Music, for me I would add it’s a reason to abandon iPhone altogether.