Flying SLC ORD, I was #1 on WL 12 hours out. Flight twelve hours out and one hour out was J1 Y0 (seatmap showed three empty F seats T1). Essentially sold out flight.

At T1 I was still #1 on WL. Flight was still J1 Y0. In a matter of minutes I went to #4 on the UG list. Mil, W,...SMI,K...SMI V, all jumped ahead of me at T1. No cancelled or delayed flights out of SLC. Made no sense to me, as they could not purchase a last minute seat as none were available.

I have taken advantage of EXP full fare Y availability when a flight was at Y0, but sense that did not happen T1.

Any thoughts on how I could drop from #1 to #4 on a sold out Y flight at T1? Not that it is relevant but I am a high spend EXP that requalified in 2020. Made no sense.