Resurrecting an old thread, but I could use some help booking a ticket to Europe next May (PDX-ZRH//MUC-PDX). Trying all sorts of multi-city tricks to get narrower search results with some success, but often many of the same errors listed above.

I was playing around with dates/routes I don't actually want hoping to learn a few tricks and I can't figure out why this one in particular doesn't work:

PDX-SEA-CDG on 5/1/17: If I search PDX-CDG hoping to get DL34 from SEA-CDG I get only two morning options to connect PDX-SEA, both on DL. None of the many AS shuttle flights that have lots of low-level award space show up. If I instead search multi-city PDX-SEA-CDG, it ignores the SEA-CDG flight altogether and sends me on long routes PDX-SEA-XXX-CDG and only with AS/AA combinations. Is there a way online to match up any of the dozen plus PDX-SEA shuttle flights with the desired DL flight?

I don't even want that flight, but it's symptomatic of the challenges I'm having and I'm hoping the solution to that will teach me how to find other flights I'm looking for.