Spotify API third party sites

[Wurmmann]

I am using statsforspotify, which uses the Spotify API. Yet in my Wrapped, an artist that was at no point in 2020 my top artist in the app, is my #1 in Wrapped. I know the cutoff is November 15, but it does not make a difference because my Wrapped #1 was never #1 in your app. Same goes for some songs, that at no point during the last few months were above the song that ended up higher in Spotify Wrapped.

How is that possible if statsforspotify and Spotify are using the same data?