I'm one member of helpdesk, and when I select a reply template that is "First Response", (the content is that your question has been received and we'll process xxx as soon as possible), then the ticket status automatically is changed to In Progress without having to select.

When I select the reply template as "Solution" (the content is that we have resolved your problem, the reason is xx), then the ticket status automatically is changed to Resolved without having to select.