I have custom code written for Automatic lead conversion am invoking the class from the Process builder if Data Quality Score is 100 . In the same process builder if the below Criteria Satisfies am creating a case. 

I have checked the option "Do you want to execute the actions only when specified changes are made to the record?"

If i include IsConverted as True in the Process builder Criteria its not creating case if i exclude that IsConverted field its creating case. Can someone tell what is the mistake here with Isconverted field.