Perhaps not fully on topic, but did you also ever needed to enter the PIN / credentials twice for unlocking the screen? For me, after entering the first time, the keypad disappears and I can see the homescreen a half of a second, then it appears a second time and I have to enter it again. After the second imput unlocking works. This happens not everytime, but very often, like every 2nd/3rd... (happens after first unlock and with P9P)