Why doesn't Program View display Scheduled Dates for some epics when those epics have Target dates?

[Nick D_Agostino]

Program View shows Scheduled Start/End dates for many epics. As far as we can tell, those dates are populated by the Target Start/End dates set in the Plan view for that epic.

However, for some significant portion of epics are not displaying any date. Upon looking, Target Start/End are populated and can be seen in the details view or in the Plan. 

Any ideas what could be causing this problem?  Thank you