Checks on [[Wikimedia:Wikipedia-library-ae475f-=7B=7BPLURAL:GETTEXT=7CContact=7CConta/en]]

It continues.

To check it yourself, click [[Wikimedia:Wikipedia-library-ae475f-=7B=7BPLURAL:GETTEXT=7CContact=7CConta/pt]] and click "Edit". It will show:
:<nowiki>!!FUZZY!!{{PLURAL:GETTEXT|Contacto|Contactos}}</nowiki>
This is the translated message, with "Contact/s" translated to Portuguese. The message is fuzzied because of the error reported. Now, remove the "!!FUZZY!!" and save it. Edit it again and the "!!FUZZY!!" is still there, meaning that the problem continues.

Now [https://translatewiki.net/wiki/Special:Translations?message=Wikimedia%3AWikipedia-library-ae475f-%3D7B%3D7BPLURAL%3AGETTEXT%3D7CContact%3D7CConta&namespace=1206 look at all existing translations]. All those that have been translated are coloured pink, meaning they have a problem. For those that are not coloured pink, most were initially translated to the target language, got the same error and then people put them in English to get rid of the error. The only exception is /fi, which was inserted by the bot already translated.

So, the problem most obviously exists! When you state that you do not have this problem, EXACTLY WHAT LANGUAGE DID YOU TRANSLATE THE MESSAGE TO SUCCESSFULLY without the problem? There is no successful translation of this message made by you.