Many of Nexus 6P users report that they find problem about their phone bluetooth connectivity. They report that their smartphones get various problems while it used to play the streaming audio bluetooth or to build a connection with other devices.
The problem manifested as stuttering or skipping sound when the phone is used to access audio streaming by bluetooth. And at other occasion, the problem manifested as the missing sounds at the beginning of the phone call or random disconnected calls. Those are quite irritating because it disturb the comfortable usage of your Nexus 6P.
From a testimony of Nexus 6P user, this problem is related to certain automobiles bluetooth or headsets. For example, Nexus 6P bluetooth audio performance is work normally on Mazda CX-5, but it stutter constantly at Chevrolet Equinox.
And for the phone calls, Nexus 6P is work normally at Chevrolet Equinox but it has problem at Mazda CX-5. This is quite disappointing because it is likely a software issue that Google needs to resolve. So if you have this problem, you need to wait that update from Google. Lately, Google did push out 6.0.1 update but unfortunately it cannot fix this problem.
There is some option you can do to overcome the problem. You can try to re-pair the devices by opening the Settings, than choose Bluetooth, and tap on the gear icon to the right of the bluetooth device you are having trouble with, then please select Forget, and you can re-pair the devices.
You also can wipe the device’s cache partition by turning off your Nexus 6P, then press Volume down and Power button together to turn on the phone. Please highlight Recovery Mode by taping the Volume down and select it by the Power button.
When Android mascot is appearing on your phone screen, hold down the Power button, then press and release the Volume up button quickly. Please highlight the Wipe Cache Partition option and use the Power button to select it.
The next is please highlight Yes with Volume down and use Power to select it. When the process is complete, you can select Reboot System now to reboot your device.
If those steps are not working, you can try a factory reset. You can do it after you back up everything in your phone and go to Settings, then go to Back up & Reset, then Factory Data Reset, and choose Reset Phone, then choose Erase Everything and please reboot.