As reported by @GrahamSH on Discord, there are "edit source" links on Special:Version/Credits on snapwikiwiki. Clicking them does not actually do anything (aside from appending additional URL parameters, that is) but it would still be good to have these misleading links removed. Thank you.
A CSS hack if used correctly would work on all skins, but I understand your want to know why it happens, it's likely an extension or something. It could probably be reported upstream even.