Gems 1.16.7.1 - XEndorse option

I am trying to set up an election for the PA Certification test and they have the option for a candidate to be a Cross Endorsement within a race. I have set up my 3 Voter Groups - Republican, Democratic, & Independent. After I have put in the Straight Party - Endorsement race, I go to add a new race and select the Straight Party endorsement option, then go to add my candidates, but the XEndorse option button is grayed out. Is this option not working yet, or am I not setting something up correctly???