OK, I am obviously visually challenged but here it goes anyway...
There is an "ACTIVE" button right above the first thread - you can use it to see what posts had recent replies.
That's all from me - I've been sporadically visiting this site since the great purge of 2015 and I've never seen this button. Anyhow, I hope this helps someone.
Tagging it for others: #ActivePosts #Active #ActiveThreads #Activity