I know it sounds crazy-- but I'm sure this is happening for me on multiple PD-6ANS dimmers and posting here may help some one googling the same issue.
Adjusting the high-end trim will often, maybe always, resets the dimmer phase to the top blinking option.
I am not sure this happened out of the box-- but it happens very repeatably for me in this state. I have https://www.amazon.com/Philips-45711...low+candelabra bulbs if it makes any difference. It's obvious when it happens for me because the bulbs buzz badly in one phase but not the other.