Yes, this question is moved from Quick Bug: My profile syas my last activity was "3 hours ago" because this is a platform bug, not a specific site bug. At least that's what I've been told, see the comments.
Basically my last activity is not updating. I have recent activity (recorded) at least 22 minutes ago but my profile on the Beta Sci-Fi & Fantasy site says that my "last activity" was "6 hours ago". It was 3 at the time I posted about this issue on the other meta site.