Back button disappeared from Apple Music

There used to be a back button while browsing through Apple Music. Now there isn't. What happened?

A common interaction pattern in the app is 1) listen to a curated Apple Music playlist, 2) find a song I like, 3) navigate to that song's album or artist page to look at more music, then 4) press the back button to get back to the playlist where I started.

This is now impossible.

The Apple Music interface has been changing all the time lately. I wish there was a stable version with basic functionality.

Screenshot included for illustration. I blacked out my playlist names, lol. I navigated to this page from my New Music Mix; no back button.