Arcam And HDMI

Hey guys - I bought an Arcam AVR360 to replace my Marantz thinking it would be a big upgrade. I ended up needing to return it for another unit because of unstable HDMI signals. I ended up buying high-end AudioQuest interconnects to make sure it was not the cabling and still had issues. The dealer I purchased from has been great so far and is sending me another unit, but I'm afraid of shaky HDMI issues coming up again. I don't have anything weird or fancy - just a TiVo an Apple TV and one of those bezel free LG panels.

If I do get shaky HDMI issues with the new unit, can any of you suggest potential troubleshooting options beyond cables?
My buddy has a Arcam and had the same issue. We found after much research, if the version of the HDMI is not correct, will have issues ie if your source is a older HDMI then the Arcam.
Thanks! I have a TiVo Premiere, which is HDMI 1.3 and the AVR360 is 1.4. If I get shaky HDMI connections again, I'll try a newer TiVo or ATV. Thanks for the suggestion, it would have not dawned on me that the HDMI version being different would cause an issue.