BLP images that aren't recognized

[Wain]

XNView is usually great for viewing blp images, but there's a small percentage that XNView doesn't recognize. I know they're blps and I can convert them to png using a converter tool (with BLPNGCONVERTER), but XNView doesn't see them as blps for some reason.

I've attached a few of them with fake .zip extensions so I can attach them here (they aren't actually zipped!). I've also attached converted png versions for reference. The file names match for the equivalent png and blp images.

The latest reference for the blp spec, that I know of, is here: https://wowdev.wiki/BLP

Thanks