Missing music on Mac and iPhone that was previously purchased.

I have purchased a number of songs on iTunes many years ago, but I can't see many of them in my "Purchased" list in iTunes Store, when looking via my Mac and using the Music app.

However when I got the individual song I purchased Iit does say "purchased" against it but doesn't allow me to download it

When I look on my iPhone I get a list of songs purchased that say "this song is not currently available in your country or region"

After reading some of the posts which suggest signing in and out of iTunes and Music, that sadly didn't fix the problem. Any suggestions please.