A:Answer I have a Comcast Xfinity X1 cable box. I have had syncing issues as well, mostly with combined Dolby Vision and Dolby Atmost content. I recommend installing the August 24 firmware update. That seemed to fix my sync problem. The firmware update may also improve other soundbar issues. It’s important, too, to download and read the separate instructions for how to do firmware updates. Pay particular attention to the instructions about how the zipped and unzipped files should to be placed on the flash drive. If that's not the same, the firmware update may not install. You need to buy a microUSB-to-US adapter if you do the update that way. I have a different TV (Sony), however, and your results may be different and require other adjustments.