Music purchased on iTunes on iPhone X/iPhone 6 running iOS 12.0.1 appearing twice in Music app

I have recently purchased several albums on iTunes using the iTunes app on my iPhone.

I download the songs, but a little while later find that duplicate entries with the "download" icon (the cloud with the arrow pointing down) appears to the right. An undownloaded duplicate appears after each track, and when I try to play the album, each song is played twice, once from the downloaded version and again from the undownloaded one.

I would like to stop the undownloaded duplicates from appearing, cluttering up the display, and interrupting an album while it is playing.

This is happening on two of my phones: an iPhone X and an iPhone 6, both running iOS 12.0.1.

I have searched for help and the closest post I have found is this: Songs are downloading twice on my iPhone and I can't get rid of the duplicates?

I have tried to follow the advice in that post, but there is no "Show all" option in Settings -> iTunes & App Store.

I can confirm that I have not purchased the items twice.

Thank you!