Open this link and inspect any collapsed lines.
https://en.wikipedia.org/wiki/Special:RecentChanges?hidebots=1&hidepageedits=1&hidenewpages=1&hideWikibase=1&hidelog=1&enhanced=1&urlversion=2
Example:
- 22:24 [[https://en.wikipedia.org/wiki/Category:Midtown_Manhattan|Category:Midtown Manhattan]] (2 changes) . . [ [[https://en.wikipedia.org/wiki/User:Ser_Amantio_di_Nicolao|Ser Amantio di Nicolao]] (2×) ]
-- [[https://en.wikipedia.org/w/index.php?title=Category:Midtown_Manhattan&curid=9288855&oldid=995594781|22:24]] . . [[https://en.wikipedia.org/wiki/User:Ser_Amantio_di_Nicolao|Ser Amantio di Nicolao]] ([[https://en.wikipedia.org/wiki/User_talk:Ser_Amantio_di_Nicolao|talk]] | [[https://en.wikipedia.org/wiki/Special:Contributions/Ser_Amantio_di_Nicolao|contribs]]) //([[https://en.wikipedia.org/wiki/3_Park_Avenue|3 Park Avenue]] removed from category, [[https://en.wikipedia.org/wiki/Special:WhatLinksHere/3_Park_Avenue|this page is included within other pages]])//
-- [[https://en.wikipedia.org/w/index.php?title=Category:Midtown_Manhattan&curid=9288855&oldid=995594739|22:23]] . . [[https://en.wikipedia.org/wiki/User:Ser_Amantio_di_Nicolao|Ser Amantio di Nicolao]] ([[https://en.wikipedia.org/wiki/User_talk:Ser_Amantio_di_Nicolao|talk]] | [[https://en.wikipedia.org/wiki/Special:Contributions/Ser_Amantio_di_Nicolao|contribs]]) //([[https://en.wikipedia.org/wiki/Lexington_Avenue|Lexington Avenue]] added to category, [[https://en.wikipedia.org/wiki/Special:WhatLinksHere/Lexington_Avenue|this page is included within other pages]])//
Notice "22:23" on the third line is linked [[https://en.wikipedia.org/w/index.php?title=Category:Midtown_Manhattan&curid=9288855&oldid=995594739|here]], with `curid=9288855`, which is for [[https://en.wikipedia.org/wiki/3_Park_Avenue|3 Park Avenue]], not [[https://en.wikipedia.org/wiki/Lexington_Avenue|Lexington Avenue]]. In any group of category changes, the `curid` for the page on the first line is mistakenly being used on all the rest of the collapsed lines.
Though I can't reproduce in markup here, the `title` (tooltip) attributes of the timestamps are also wrong: they're set to the name of the category, not the linked pages themselves.