osTicket v1.10 (stable) and Maintenance Release v1.9.15 are now available! Go get it now
Tickets keep the assigned agent after you reassigned to a team
After ticket have been assigned to an agent, this agent remains assigned after you reassign the ticket to a team, the system does not clear out the agent from the ticket.
Agent do not want to keep the ticket is their list of ticket after they reassigned to a team, there are several reasons, ie when a ticket was wrongly assigned to a agent.