Go to the Settings menu of your device
Find and press sounds and notifications
Then tap Do not disturb
Then tap Auto Rules and set up a custom rule. Remember that this new custom rule should start in the past and should end around 5-10 minutes from the time you set it up.
This will put your device in sleep mode for the number of minutes you have chosen. Once the time has elapsed, the rule will expire and your device will automatically navigate here disable Do Not Disturb mode. This is a workaround that many users have tried and it worked for most of them.
Another workaround that has helped users is to switch the volume knob to vibrate, then back down to silent mode. Then bring it and you will have the option to turn off Do not disturb. Tap Finish now and see if the problem is resolved. Tipping the volume will help you turn off Do not disturb so that you can use your device as usual. But if your Nexus 6P Do Not Disturb problem is not resolved yet, then follow the next solution.
Some users have found that the problem can be solved by modifying some DND settings that will help you to turn off the Do Not Disturb option on your Nexus 6P. Follow these steps to solve the problem: