Most of my songs have been edited in Song Info (right-click in iTunes on a song/album/artist and select Song Info). Here I changed the start and stop time and whether I wanted to skip the song when shuffling. The problem is that these changes don't appear when I sync my library with my Android device (Mi 9t). I have an Apple Music subscription.
Any idea what to do?
Editing the song in iTunes simply sets the configuration for that song locally in iTunes.
In order to commit it to the music file permanently, you will need to export it to an AAC file by going to File > Convert > Create AAC on each of the song you have set the start/stop times for.