Why is the audio out of sync on my Amazon Fire TV Stick?

We’re aware that a number of users with Amazon Fire TV Sticks have experienced problems during playback when the audio is out of sync with the video. 

If you are experiencing this problem, please make sure that your firmware is up to date. We know that using the TV USB port to power the Fire TV Stick will drop frame rates which can cause audio sync issues so please use the main power supply.