I just tried to close a ticket. I went to "Update metadata" and saw "Closed as" dropdown menu. I clicked "duplicate" and then "Update". Nothing happened. Repeated several times, did refreshes. Nothing.

Turns out you have to first set the status of the ticket to "closed" and then select one of the reasons from "Closed as".

"Closed as" should be hidden if the status of the ticket is "Open". Or even a better idea: the "Status" menu is redundant, you either want to close the ticket (possibly with a reason) or reopen it. That means that there should be a button that would allow either to close an issue with a reason from a dropdown menu, or a button to reopen it if the issue was previously closed.