I've noticed that the EUA process seems to be running at a different time than before. Since the beginning of the year, I've received my EUAs around 10:00 PM CST. Before they seemed to come through just after midnight. The CSR supervisor said that the cut-off time for booking to make the EUA run for that day is 6:00 PM CST, so that implies to me that the process is running not too long after that.

As Channa pointed out, maybe a bad record stalled the run for my flight. I will certainly pursue the matter with OnePass. Kind of disheartening to find out that the EUA process is not as cut and dried as CO leads me to believe. Again, if CO wants to hold the FC seats back in order to sell them, more power to them. But I've always been told by CO that if the R seats are there they're available for upgrades during your window, and that doesn't seem to be the case anymore.