Not able to close the service request,All Tasks statuses are in closed.

Dear Gurus,

We are getting the below error message while closing the service request. In tasks tab, all tasks are in closed and completed status even though we are getting the open tasks error message.We have not checked the restrict closure check box also.

Error Message: There are open tasks in this service requests.Please close these tasks before closing the service request.

Please help me on this and find the attached screenshot for error message.

Profile Values:

Service: Auto Closure of Service Request set as site level "NO"

Service: Service Request Auto Close Status set as blank

Service: Default value for restrict closure flag on service request task tab set at site level as "YES"