Why is quiet mode not abiding by the scheduled times? Ever since my phone upgraded itself to Android 4.4.2 a couple of weeks ago, it has trouble turning quiet mode on or off at the set times. 

I have it set for quiet between 10 pm and 8 am, and the indicator by the "Schedule Settings" is blue indicating that the setting is on, and the moon icon with the timer remains in the top bar, but it either doesn't switch into quiet mode or if it does happen turn on at the scheduled time, it doesn't turn back off.

If I cycle the "Schedule Settings" switch, it does go into quiet mode for that night, but does not always do so the next evening.

Is this a bug that was introduced with the upgrade, or is one of my apps intercepting the quiet mode setting and overriding it?

I'm using an LG G2.
I had the same problem and found a workaround by going to settings->sound->quiet mode and repeating toggle "turn quiet mode now" until I see the notification on the notification bar. After that the scheduled quiet mode will work, but you had to do this after every restart of the phone.