I have a Samsung ks8000 tv hooked up via ARC to a Denon x2300. They are connected to each other using two HDMI 2.0 (with Ethernet) cables and an an HDMI extender that all support ARC. ARC was working (when watching on the tv's Netflix app) for 8+ months until a few weeks ago when it started working interminably (video is fine, but the sound isn't making it out of the speakers hooked up to the Denon receiver). I tried swapping out the HDMI extender, but nothing changed, which makes me think it's either the tv, the Denon or the Cables. I've made sure the tv and receiver are both fully updated and the ARC settings are appropriately turned on. Any suggestions? I'm struggling with how to troubleshoot because sometimes it works and other times it doesn't. If it consistently didn't work, it would be an easier thing to troubleshoot.