There have been times when I've lost the ability to play downloaded albums on the Qobuz app. When I contacted them about this, I was told that when the license for Qobuz to offer the album expires they have to take it off the site. I complained that the website said the user retains the right to listen or download it any time. So what did they do? They changed the language on the site! So always make sure you download your purchases right away and put them in your media library, at least then they can't take it away from you.
This happens on other sites as well. One artist on Bandcamp left a small, Bandcamp-supported label and signed with a major label, which re-released her album which I had "purchased" and downloaded. So Bandcamp had to take it off the site, presumably for legal reasons. I can no longer listen to it on the Bandcamp app but it is in my music library.