[Q] Power button is not locking/turning off screen but works to bring up power menu. topic

So this morning I picked up my Note 4, used it normally to check emails, etc, went to turn off/lock screen and it wouldn't respond at all. I held down the power button and then it brings up the power menu, I restarted a few times and still nothing. Is my power button defective or could some setting have automatically changed the settings?