Default Screenshot button combination not working

It may be a simple issue to fix, but it's annoying that I can't capture my screenshot the power button and volume down combination capture screen. I'm having to go to power menu and selecting screenshot.

Any thoughts as to how I get it back to default?

I'm using Paranoid ROM 4.1-Beta 2.

Sent from my Nexus 5 using xda app-developers app
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