Another example: this edit should have moved the page out of Category:United Kingdom articles missing geocoordinate data and into Category:Orkney and Shetland articles missing geocoordinate data, but it didn't, although the cat list in the article was updated.

This is affecting more than categories. @ShakespeareFan00 ran into this when doing some SQL queries, and discovered that (for example) https://en.wikipedia.org/wiki/File:MovableBridge_roll.gif doesn't seem to have any templates on it, according to MediaWiki (https://en.wikipedia.org/wiki/Special:ApiSandbox#action=query&prop=templates&format=json&titles=File%3AMovableBridge%20roll.gif), despite the page clearly including a template (https://en.wikipedia.org/w/index.php?title=File:MovableBridge_roll.gif&action=edit). This page was created on 5 November. We've seen some other ones, but "broke" the examples by null-editing the pages, which usually fixes the problem.

https://en.wikipedia.org/wiki/File:Agraharam.jpg is older, 26 October 2015‎, same issue: https://en.wikipedia.org/wiki/Special:ApiSandbox#action=query&prop=templates&format=json&titles=File%3AAgraharam.jpg

Another example: this edit should have moved the page out of Category:United Kingdom articles missing geocoordinate data and into Category:Leicestershire articles missing geocoordinate data, but it didn't, although the cat list in the article was updated.