Forum suggests old topics as “New & Unread Topics”

Why is the forum showing old topics as “New & Unread Topics” when looking at a new topic?

Correct, the Forum is it,
this service is setup and paid for by Athom for the Community.

There is a perfect community for that here: https://meta.discourse.org/

You probably didn’t read all post in these topics, even the Posts read status is tracked.
fe if I open an old topic shown below that has one or more post that I didn’t read yet:
image
I see a couple of seconds the blue dot.
Also see: What is the difference between "entered" and "read"? - #10 by codinghorror - support - Discourse Meta

so depending on that you are reading, Discourse shows you topics with unread messages that might have a relation (and maybe not)
(even for me Homey Community Forum )

You could ask the creators of Discourse at the forum mentioned above.

1 Like