Seems to work fine for me: https://de.wikipedia.org/wiki/Spezial:Letzte_%C3%84nderungen?uselang=de-formal

On Fri, Jul 22, 2022 at 7:05 AM RhinosF1 - <rhinosf1@gmail.com> wrote:

It is probably worth opening a bug on Phabricator. As far as I can tell Special:MyLanguage (https://github.com/wikimedia/mediawiki/blob/master/includes/specials/SpecialMyLanguage.php) does not include any logic for using the fallback languages which for de-formal is de.

It's right there. Of course, that's based on the language you have set on mediawiki.org, not the linking wiki.

In any case, the SpecialRecentChanges help link is hardcoded to https://meta.wikimedia.org/wiki/Special:MyLanguage/Help:Recent_changes , language settings have nothing to do with it.