I am going to SXM and would need IAD-SXM on a nonstop flight and for the return SXM-EWR-IAD. I want to add a "free one way" ie a stopover which ideally would be in DC. When searching online for this itinerary, I can do a simple IAD-SXM-IAD//IAD-SFO which has the SXM-IAD connect in EWR with no problem which prices at 52500 (standard award needed for the outbound). If I try IAD-SXM-IAD-DUB (or any European city), the only option for the segment SXM-IAD involves a connection in PTY on Copa. I'd rather have that flight via EWR. Is there a reason why it may not show the SXM-EWR-IAD//IAD-DUB flight? As a side note, IAD-SXM-EWR//EWR-DUB works fine and prices at 62500.