This is somewaht of a sore point.
On "old" AB when one answered a question and then referred to it later the answer appeared by when you gave it,not by when the question was posted.
As you have found (I think) on this "new" AB the same does not happen with "threads I am involved in".That is when you refer back the questions are listed by when they were posted,not by the date you were involved in them;which of course sometimes makes them very difficult to find.
AB Ed has been asked to change this back,but like SO MANY other things it has not been sorted out,if it ever is!