Purchased singles not included in full album on Music app

For years, I’ve always found an issue for when an artist brings out an album where the singles of the album shows as ‘purchased’ on the album, and then when the album’s released and I buy it, in the Music app, on the album, these singles, although ‘purchased’ don’t show as part of the album, so I can’t listen to it in full.

For example, Perrie has just released her album, and the single ‘If He Wanted To He Would’ was released before the album was announced, so I had bought that, and when I pre-ordered the album, it showed that the song was already purchased. But now that the albums out, that song isn’t included as part of the whole album in my Music app. I’ve attached pictures of iTunes and the Music app to show what I mean.

If anyone has a solution, that’d be great! Thank you!

[Edited by Moderator]

Original Title: When buying an album on iTunes, if there are ‘purchased’ songs on there, why don’t they show up in the full album in the Music app?