A bug has been reported with the “merge” feature, where merging two non-deleted posts does not update the page automatically meglio. Instead, the page only partially updates, removing some messages, but not updating the last message until a page reload meglio. codinghorror initially questioned the use case, but meglio clarified that the issue occurs with non-deleted posts. tgxworld and adrapereira have been notified, and tgxworld has taken a look into the issue, submitting a pull request to resolve it tgxworld.
Yes. However, it is seen as a bug by staff members, because the page does get updated automatically, but only partially: some of the messages get deleted (highlighted in red immediately), but the other (last) message gets no updated. Thus it looks like you just removed a few messages and this is it… until you refresh the page and realize the messages were merged.