"Last activity" in question lists appears to ignore new answers
Another thing I've noticed on https://outdoors.codidact.com/categories/19 : the question list currently shows the last activity on "2020 - May - Birds" as "last activity 10 days ago by Isaac Moses". It's not clear to me what this activity was*, but certainly I posted an answer 3 days ago and I think that should count as activity.
* If the question list is showing activity on the question post rather than the thread as a whole, that breaks my expectation. But the question post's history doesn't show any activity by Isaac, so it's pure speculation that that might be the cause.