(Voyager 1.29.0, iOS, iPhone SE2)
Despite setting the app to sort by Hot, re-applying said setting, and manually sorting by Hot, the sort always changes back to Active once I leave and re-enter a feed.
This just started happening with the latest iOS update.
Edit: Problem resolved itself after re-applying the setting over and over. Probably not an actual bug.
Active also triggers if old-ish posts have new comments in them. Which is why you get 4 day old posts when the have set the feed to sort by Active