It appears that the Audio Return Channel (ARC) on my Samsung Q80 Series TV no longer works when the TV upgraded to T-MSMAKUC-1372.2. The ARC was working fine with my Onkyo Receiver before the update then it stopped working. I have reset the TV three time and it has not resolved the issue. I have unhooked all devices connected to the TV and that did not work. The TV does recognize the receiver at the HDMI port as a device but the ARC does not return sound to the receiver. I even tried my brother-in-law's Onkyo Receiver, same model, and it also had the same results. Any ideas how to resolve this, revert to the previous upgrade, or report a defect?