I just merged two topics with the ‘move to existing topic’ function and found that all the posts from the newly created redundant topic were randomly shoved into a timeline from about a year earlier and the ‘latest’ post is from Oct 2016 despite the new content coming from the last couple of months.
In the overall view on the main page it shows the poster and date from the newest posts that should be there, but the last post is actually from the previously untouched thread.
This seems buggy, but is there a solution to correctly reorder them with a command?