AppleMusic playlists

I recently created a playlist on my phone with my Apple Music account and downloaded all the titles. After a few days several titles went missing, so I downloaded them again. I felt quite gutted.

Now, after opening that playlist again after a week there is no song left. A playlist of 60 ties gone.

Still, apple music still works. l can listen to all the music I search for, just the playlist function seems to be utterly disfunctional and leaves me wonder if the competition doesn’t do a better job and that I mightbe better off switching services.

Any idea how I can download and not lose song?

Thanks to all!