All album downloads gone but they have remained saved? Playlist downloads unaffected

[Pawelm]

All my album downloads have gone today, but Playlist downloads have remained? This is a peculiar bug as it deleted all my album downloads (1,500 or so) but left them in my library as saved. This has happened on some scale beforehand but usually it would leave the download as gray, meaning it would redownload by itself when connected to WiFi. This time however it looks like I never downloaded it in the first place which is extremely frustrating. Now I have to single handedly re-download all albums.

Could you explain why this has happened and how I can avoid it happening in the future?

For the record my Spotify premium is recurring and I had more than enough storage on my phone.