Ha! Guess there are multiple Apple Music regressions. Just upgraded to 27.0.1 on iPhone 13 Mini My regression is when playing local music in a playlist, if you try to manually seek when a song has less than 10 seconds left it jumps to the next song on the screen while the prior song continues uninterrupted and stays in a confused stuck state until the next song begins. Sometimes the counter for the next song begins while the last song is still finishing. Once the new song stats the counter "adjusts" itself and then we continue onwards.
I remember from an old CCC conference they talked about looking for vulns in specific portions of the OS that have had UX changes like this as it may indicate a lower skilled developer having to show that they are getting tickets done. Code that was solid ends up introducing bugs. Areas of the OS untouched have less likelihood of easy to find bugs. I don't know how valid that theory really is but your example makes me think I have to start wasting time monitoring the beta program to see what changed and if my most used app features are touched I wait until at least the .1 release or now probably .2 release. Problem is with the advent of AI assisted hacks, it feels like I should update the nanosecond something new comes out.