Some of my music I purchased is not appearing on iTunes (iPhone and Mac) and they are not downloadable, but it shows as purchased when I go to the iTunes store. It also doesn’t appear listed on my purchases list yet it shows purchased in iTunes Store

Some of my music I purchased is not appearing on iTunes (iPhone and Mac) and they are not downloadable, but it shows as purchased when I go to the iTunes store. It also doesn’t appear listed on my purchases list yet it shows purchased in iTunes Store. I have no idea what’s happened or why certain purchases have disappeared, but I cannot play any of them (and I paid for them) so this is highly frustrating