Try uploading your asset packs as .zip files instead of .png files :)
With your being an admin, I'm sure that should work and I will try that.
But really, why is that a thing? Why in the world should file type matter, and does the upload-module mention this at all? Because if this is why my stuff doesn't pop up, the uploader should tell the user to submit a zip to increase visibility. Also, does this apply to .exes, .pdfs, or any other file extension? I seem to remember being able to search up a few of those that weren't in .zip format.