Is it intentional for /recent and /category -> sort by newest to oldest
the result is sorted by recent activities (post created time) AND not by topic created time?
@MJ I'll just create an issue for you so you don't have to worry about it.
For future reference, though:
You go to https://github.com/nodebb/nodebb/issues and click on "New Issue". If you don't already have an account it will ask you to create one, then you can report an issue.
There may be a small chance that old topics on this forum don't have their bookmarks set properly. We switched from pids to post indexes, and any old bookmarks might still be referencing the pid.