"Built from: [Deleted this reference myself] (Pre made SD website)" This site only supports the RetroPie images hosted here. I use the K400+ and mine has no problem working as a controller from ES.
Download and burn the SD image hosted on this site, and not only is it likely to work, but we will actually be able to support it!
https://retropie.org.uk/download/
EDIT: I just noticed that is a pre-made image site complete with copyrighted games included in the image, so removed my reference to it from your quote. Links or mention of images or sites distributing copyrighted games and/or BIOS images are also not allowed here....