Why are no records returned when I filter for a Primary Role on the Role Capacity Histogram portlet under the Capacity tab under Resource Planning?

However, if we clear the filter, there is data for the roles we are searching for.

Release: CODFSS99000-15.3-PPM SAAS FedRAMP-Sandbox-Small Environment
Component:

The portlet returns data for roles and roles do not have the ability to have a Primary Role. 

The Role Name filter parameter should be used when filtering on this portlet instead.