Assigning Tickets in Zoho desk

Assigning Tickets in Zoho desk

Hi Team,

I am trying to assign a ticket to another person from another department. Although, the ticket has been assigned to his/her queue they are not able to see the ticket in their list. When I searched by providing the ticket# in their department no tickets have been found. 
Why is this happening? Are there any settings changes to get this done? 

Thanks in advance.