Hello, on Sicilian language there's a namespace name that must be changed. Ns 828 now it's written in italian ("Modulo"). The name in Sicilian is "Mòdulu".
Looks like it was falling back to Italian because there was no Sicilian translation set. I've added it on translatewiki.net: https://translatewiki.net/w/i.php?diff=10441954
To help translate MediaWiki, see https://translatewiki.net/wiki/Translating:MediaWiki