Yes, I know but, it seem like something wrong with itThe only thing I know is that "prevent accidental wake up" uses the proximity sensor and the light sensor to determine if the phone should wake up. For example, if the proximity sensor detects a close object, and the ambient is dark, the phone will not show the lock screen even if you press the power button. It will display a warning text which asks you to press and hold the power button.
You can check this yourself in a dark room. Enable that option, cover the upper part of your phone near the earpiece, and press the power button.
I will try again tonight to check about this last time
/tested, the problem is back