When not logged-in to Wikimedia Commons, some non-empty categories are showing as empty.
When logged-in to Wikimedia Commons, the categories are displayed correctly.
Examples follow.
*Please log-out of all Wikis before trying this!*
Some of the four child or grandchild categories of the category https://commons.wikimedia.org/wiki/Category:Locally_Listed_Buildings_in_England are showing this problem, here are examples:
Go to this category page: https://commons.wikimedia.org/wiki/Category:Locally_listed_buildings_in_Brighton_and_Hove, and click the category link 'Locally Listed Buildings in East Sussex' at the bottom of the page. You will be taken to the 'Locally Listed Buildings in East Sussex' category, but that category is erroneously shown as empty.
Another example: https://commons.wikimedia.org/wiki/Category:Locally_listed_buildings_in_Birmingham, click on the 'Locally Listed Buildings in the West Midlands' category at the bottom of the page, which is then erroneously shown as empty after it is displayed.
Another example: https://commons.wikimedia.org/wiki/File:Tram_Shed_Military_Road_Colchester_Essex_England_UK.jpg, click on the 'Locally Listed Buildings in Colchester' category at the bottom of the page, which is then erroneously shown as empty after it is displayed.
When logged-in to Wikimedia Commons, the categories all show correctly.
*After viewing the categories correctly when logged-in, they then sometimes show correctly when not logged-in afterwards - maybe they are cached in the browser, I am not sure.*
I have tried this with Firefox (latest version) and Chrome browsers on Windows.