I have the roku smart soundbar and it worked with my old sharp roku tv (not 4K, about 43”) just fine but with my new 65” 4K Vizio m656-g4 it works fine except occasionally when I turn the tv it makes this super loud noise, like if you put metal in a blender or something. I’ve replaced the hdmi cable, tried replacing power cords to the tv and roku, tried different power strips and plugged directly into the wall, and I tried resetting factory settings on both the tv and soundbar. Each time I try something it works fine for a week or two so I think it’s fixed then it happens again. The hdmi is plugged into the ARC port on the tv per instruction. I’m out of things to try, any advice would be appreciated!
If you are still unable to resolve the issue, please send me a PM (private message) with your Roku account email address, and include the serial number of the Roku device from Settings>System>About along with a summary of the issue you are experiencing. I'll be able to assist you further from there.