The sweeps do seem to be running at different times of the day lately. I got one today for MCO-DCA on Sunday, a couple of days after the CP window. It came in around 3pm and it's an evening flight which may have something to do with the timing. I did not call in to kick-start it but I did get a No Upgrade Available email at some point Sunday (window).

They are holding seats longer for purchase which doesn't bother me. This explains why there is F inventory but manual upgrades aren't possible. And as frustrating as it is for some, I still am glad that they're not seccessful in manual upgrades because then we go back to upgrades based on fastest finger and not by status.

Just checked the timestamp on an upcoming Phl-Ord and my upgrade email came in at 1pm on that one (but at the window).

Maybe they are staggering the times on the email blasts?