Thanks @jonas, all I see is that it uses QUrl and fails.. here's am example where I replace some strings with ???
15:40:34.649 DEBUG DiscogsCoverProvider:185 Discogs: Sending request QUrl("https://api.discogs.com/database/search?key=???&secret=???&format=album&artist=???&release_title=???&type=master")
15:40:34.650 ERROR DiscogsCoverProvider:477 Discogs: "Host api.discogs.com not found (3)"
I guess I'll have to update eventually..