I noticed when attempting to price a multi-city itinerary that most of the fares in the chart are empty. But they show up if I try to price it as a normal one-way.

Example:
SEA-SAN 7/16

Has bargain through FC available as a normal booking (and a few hot deals as well).
As part of a multi-city itinerary, I get (hot deals or bargain; never both) and FC. No value or full flex.

And U availability doesn't appear at all, though the comment about the gold/blue U does appear at the bottom of the page. Why wouldn't they display that for a multi-city itinerary?