As an instance, a new user has recently registered at the online swim community with the username "swimatlanta 0". I have not observed any other users with the name "swimatlanta". Do you think the reason for the "0" at the end is that we have a group named "swimatlanta"?

Excellent, you rock!

Thanks @baris. I also figured out that the group member created the post before the particular category was set for this group. So the old posts in a different category still show. And as you said they will be gone after new posts are posted by members.
Another possible issue is that when the member left, his/her posts are still kept there. But it may be okay.

I created a private group and specified a particular category ID to only show posts from that category. However, upon viewing the private group page, I noticed that posts from other categories, made by group members, were still visible. I am unsure if this is a bug or if there is something that I overlooked.

Group Settings

Group Landing Page

Thank you. @julian I realize now that I should have posted my comment in that thread. However, I find that the thread has become quite lengthy, and difficult to find what I look for. Perhaps creating a sub-category with separate threads for each issue, or even using Github Issues, would be a better approach.

Regarding the issue I had, it appears to be a simple fix by adding the "alert-link" class. As per the documentation, "Use the .alert-link utility class to quickly provide matching colored links within any alert."

The hyperlink on the message box is hard to read.

Thank you! Will do.

Do you have an estimated release date for V3? I'm planning to set up a new community website using NodeBB. Would it be better to install the V3 beta or wait for the official release?

Freshly installed NodeBB a few minutes ago. It showed V1.16.1 in the dashboard and asked me to upgrade. Then I followed the instruction on the upgrade page, but still got V1.16.1. Waiting for the fixes.