Sometimes you may experience buffering due to low internet speed or high internet traffic.
The most common cause of buffering is the result of slow internet connection. This may be because of low internet speed or other users hogging the bandwidth in your house. Do you have lots of users in your home? Disconnect them all and try again.
The second reason is that you are using Wi-Fi, which is not suit for watching TV as you need direct (LAN) connection to internet network in order to enjoy smooth watching without interruptions.
Directly connect to your router using an LAN (ethernet) cable or to a powerline adaptor.
If not possible, try moving the box closer to the router.
Change your WI-FI channel. To avoid interference with nearby devices.
If you experience buffering press “pause” for 10-15 seconds and resume, most of the time that will eliminate the need to buffer.