Originally Posted by jsloan

The agent is correct — the lowest available inventory is Q..


This is partially correct, but your conclusion is wrong.

Yes, the app is essentially showing phantom inventory. That’s because the target set of flights is available as a married pair — you can see the inventory in ExpertFlyer. However, United’s pricing engine is willing to insert a fare break on a connecting itinerary when attempting to price it. It does that when the price is lower than the corresponding through fare. When that happens, Expert Mode shows the individual, “divorced” inventory for each flight. That inventory is not available for a flight change. That’s why the agent isn’t able to do it.

OP: Try using the regular flight change tool, instead of the SDC flow, and use multi-city search. It’ll require changing your existing flight to DCA-IAH, and then clicking the “Add flight” button and adding IAH-FLL back in. I can’t promise anything, but this might get you access to the same inventory you’re seeing in expert mode.

Alternatively, since you’re already booked on that same routing, you should be able to standby. Assuming that you clear the DCA-IAH leg, you should be able to SDC the IAH-FLL leg after boarding.