When using checkuser form on a Non-English language, the URL created gets the "special" namespace according to the language. For example, the URL created when clicking on Portuguese Wikipedia is https://meta.wikimedia.org/wiki/Especial:MultiLock?wpTarget=
It comes with "Especial" instead of "Special". Maybe you can fix the link so it can't be changed by local language or you could created some sort of redirect on Meta from "Especial" namespace to "Special". Just some thoughts. Thanks.
I have added Glaisher as subscribed. I hope you don't mind.