I cannot get my 7.1 surround sound to work on my amazon fire stick. It only plays out of my from 3 speakers. I have the fire stick plugged into the DVD hdmi on my Denim 3311. I am not sure of that is the issue or not. Does anyone know hot to fix this? I have the new Amazon Firestick with Alexa if that makes a difference. Thank you in advance for your assistance.