Well, I gave up and checked for flights out of IAD, which is also near me. All of the United "saver" flights showed up, and I was able to book another flight using Aeroplan. Oddly, the BWI flights were still missing. Not quite as good a time of day for me, but it was worth it to just put this to bed and get a ticket.

Hope they fix this, and hope that it is a glitch.