After going from the main page to a Category and then sorting that page by replies, view, or activity and then going to a thread from that view, clicking back on the browser does not return to the sorted category page but instead returns me all the way to the main page. Previously the behaviour had been to return to the sorted category page.
Since today I have this behaviour. Only checked with Firefox but it was not doing this yesterday with the same browser+version, and my system has not been updated in the meantime.
(I use this sequence always when browsing the updates sections since - for me - it is more important to see newer posts than newer topics.)
Maybe Discourse changed something with the forum? Any chance to change it back? Or perhaps others do not see this...