ServiceDesk 7.5 SP1 Subtask deletion

We have upgraded to ServiceDesk 7.5 SP1, and have issues with subtasks being deleted. If we close out the parent ticket, it will delete all subtasks from the ticket.

In our Servicedesk 7.1 environment, the subtasks would stay open until they were individually completed.

Is there a workaround to mimic this in 7.5?

Thanks,

Steven B.