Default Proximity sensor error on CM11

I'm running latest cm11 nightly (27Jan) on my Samsung Galaxy S4 I9505 international version (jfltexx), but noticed the proximity sensor is broken since quite a few nightlies ago.

When I take a call, the screen goes off, but then it never comes back on again until I press the power button, or after a long delay. Checking with cpu-z, the sensor initially detects 0cm when u touch the proximity sensor, but upon lifting finger, it never gives a higher value (usually limit at 8cm). I can't post to the cm11 development thread to get help on this (maybe coz I've not chalked up enough post counts). Any idea on this will be much appreciated, thks.

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