Step to reproduce:

1. go to RecentChangesLinked
2. type a category about which you want to see recent changes (Category:Brittany for instance; on fr.wp, the case is about Portals, like Portal:Rennes or Portal:Judaïsme)
3. a list of new changes loads, you can see some results
4. change the category (Category:Paris)

Expectation: a new list of changes is displayed

Reality:

• list of results remain the one for the former category
• the URL is updated in the browser, so refresh the page works

Tested on en.wp and fr.wp, both logged-in and not.