We have an issue after an agent is merging user accounts.
After the merge, it changes the requester, and when the agent returns to the ticket, this change doesn't show there. After that, the agent tries to solve the ticket and sees the error message: "Ticket not saved."
It seems like the change on the requester doesn't happen on an update for solving the ticket, and agents need to do an extra step to update it to any other status and solve the ticket afterward.
I created a ticket on your behalf so that one of our Engineers could check the affected ticket that you mentioned and review the ticket events to fully review what happened on the ticket. They'll reach out to you via email!