Thanks for your help friend. I found the solution. It was because of the turkish translation. I made the system lang english and made the vibrate on touch "off". Then made it turkish again now nav buttons do not vibrate.
Hi friends. I can not disable navigation buttons vibration in sound settings with new miui 8 latest weekly rom. I made the vibration on touch off in sound&vibration settings but navigation buttons still vibrate. Any suggestion?? Thanks.