IOS 10 on iphone 6

I recently updated my iphone 6 to IOS 10.0.2. Now i have a problem with my side buttons for ringtone volumen. Every than and than the phone switches between the ringtone setting and the volumen setting ( it is just for watching videos ) so i can not set the ringtone volumen with my side buttons any more. Than i shut down my phone and when i start it again it works fine for a few moments. Does anybody has the same problem.