Closed tickets displayed whereas closed option deactivated

Some Closed tickets are displayed whereas closed option is deactivated.
I think it is the tickets closed with the Kanban board (move of the card)

Thanks for your help
 

Thanks a lot for your reply. but I d'ont really understand the usefulness to have the closed status and checkbox not always synced ?

In my case, I do a very simple test :
1/ I create a ticket and I closed it (in the "ticket page") => the closed ckeckbox is checked and the ticket is really closed (OK for me)
2/ I create a ticket, I drag and drop the ticket in each column (in the kanban page) until the Closed column => the closed ckeckbox is unchecked and the ticket is not really closed.

There are several impacts :
  ==> the ticket is displayed in the tickets page with closed option not checked
  ==> I can modify information on a closed ticket (strange)
  ==> I can't close my activities linked to the ticket because Projeqtor says that they are linked to an open ticket...

I understand that the "closed" option is linked to the "closed checkbox" in the ticcket and not the status. Now I know how to correctly close my tickets (with this checkbox).
But is it normal that, when I use the kanban Board to close a ticket, this closed checkbox is not checked ?

Thanks a lot

 

Thanks for your reply.
I actually work on the v9.2.2 on production and v9.5.3 on pre-production. The issue is still there on the 2 versions.

Thanks a lot