Some items that have labels (and descriptions), such as in the user language or other languages, don't have these displayed in the "other languages" box on the page:
we purged the parser cache (and I also tried purging manually and editing some of these items). None of this helps. Clicking random or nearby items, some are affected by this bug and others not.
Now that I look at my local wiki, this is easily reproducable and thus hopefully an easy fix.