The checkboxes that change a ticket's properties do not have a None option in the Team selection in order to unassign Agent Team
官方回复
Christine Loh
We are glad to inform you that this feature is currently available. When replying to a ticket, you are now able to select the Team checkbox and in the drop-down menu, select Unassign Team. Once you send a reply, the Team will be set as Unassigned.