You Can Downgrade from Android 6.0.1
If you can't find a fix for your Android 6.0.1 problem and you don't want to wait for Google to roll out the next Marshmallow update, you might want to think about downgrading or installing a custom ROM to see if that helps.
We've put together a guide that will take you through the Android downgrade process. (The guide is for Android 5.0 Lollipop to Android 4.4 KitKat but the process is similar).
The process will take a bit of your time so you'll want to set aside some quiet time so that you can learn about the process and address any problems that come up. And yes, you might run into some problems, especially if you're a novice user.
If you want another resource, here is an additional guide that will show you how to downgrade the Nexus 7 from Android 6.0.1 to something else.