Windows shows some thumbnails of Designer files razor sharp and others, with exact same dimensions and dpi, and even exact same files but re-saved, blurry.
Looking at the thumbnails below, the left one is the thumbnail of an exising afdesign file. The right one is the exact same file, but opened in Affinity Designer 1.8.5.703 and saved to another name.
So for some reason newly saved afdesign-files get a very blurry icon while older files have perfectly sharp icons.
I include the original afdesign-file as an attachment.
buffer.afdesign