luceos hi, it seems I have figured out what's the issue, so I would like to report a bug. Here is the link to my post on FreeFlarum's support forum; everything was discussed there, but I'll also write here what I've learned.
We have Approval extension turned on, so nobody but admin can post without approval. When we turn that extension off, or we are posting from admin account, then the discussion in the tag list is updated immediately.
From what the developer at FreeFlarum said, it's probably a bug in the Tags extension, and likely the conditional check will need to include a case for the Approval extension.
I was not sure where to post that, so could you please help me forward it to the right person/team? Thank you for your help.