At wikimaniawiki, I think the interwiki table is misconfigured, such that [[wikt:en:foo]] will create a hyperlink to https://wikimania.wiktionary.org/wiki/en:foo
Test cases: https://wikimania.wikimedia.org/w/index.php?title=User:Quiddity/sandbox&oldid=1921
Screenshot comparing Enwiki to Wikimaniawiki (Special:Interwiki of both):