"Critical Alert Due Date has been reached for a task" notification triggers to employee's ex-manager

Summary:

Hi,

The performance notification "Critical Alert Due Date has been reached for a task" triggers to the ex-manager of an employee. The employee's manager already changed and the last assignment number is also terminated and new assignment number created for that employee where manager is a different person. But still the ex-manager receives an email on daily basis to complete the evaluation for that employee.

Could someone please give me a solution for the same? How do I stop this critical alert from the ex-manager?

Thank you in advance.

Regards.

Narendra