email encryption using smartcard cert on Catalina update issue

I've recently updated to Catalina and am trying to get email encryption using a cert on a CAC smartcard to work. When I create an email with my CAC card inserted I see the encrypt button grayed out and the signing button enabled. So I can sign emails with my CAC cert but not encrypt them. Because I updated to Catalina I followed instructions to remove all old CAC card software I'd previously installed (http://militarycac.com/macuninstall.htm). Any suggestions for what I need to do to get this to work?