Hi! 
While continuing our saga of having quite a few customers not responding to the auto response of an existing ticket, I have noticed that even though our “Ticket Last Contact Behaviour” is set to Use the time of the very last customer article., merging tickets does not update a tickets last contact time to reflect this.
This is an issue, as our overviews are sorted by last contact time and we expect users to be able to bump their tickets.
So for example; there is a ticket which is weeks old, and the same customer opens up a new ticket related to the same case. Merging these tickets does not update the last contact time, causing this ticket not to show up in the top of our overviews, even though technically the customer just added a reply to it.
This almost feels like a bug to me as the setting states “very last customer article”, which after a merge no longer holds true.