I stumbled upon this when trying to upload a deb package for vector:
https://github.com/vectordotdev/vector/releases
All of their releases seem to behave that way and the fix is indeed to repackage them. I'm fine doing that, but I thought you might like a package with which you can easily reproduce this behavior. Maybe ProGet could be a bit more lenient with the tar files it accepts, or maybe it's actually a bug.