How exactly does the "Recent" Tab work?

So I made a topic in Forum\ChitChat\People & I've noticed that despite getting replies it is not coming up when I click "Recent".

& now that I really consider the threads in Recent, I'm noticing a trend that seems to lack certain Forum trends aka anything not in 1 or 3 "Main" forum Topic archetypes.

I almost exclusively use ATS on my phone & purely rely on "Recent" to follow the activity & suddenly im feeling very under exposed to where people are chatting on the forum.

a reply to: Eunuchorn

When you click on Recent it gives you a list of recent posts on the ATS side of the boards. If you click on the smiley face it takes you to the posts on the Off Topic side of the board.