We had the same problem after using the HDMI on our new TV for a week. They also told us at the time it was software related and to wait for the update.
Then, on the most recent Techical Forum, they mentioned a hardware problem with the 622 and HDMI connections saying that if it had worked and then suddenly quit working it was a hardware problem.
After hearing that Forum, I called Dish and requested a repacement 622 based on what they said on the Technical Forum. After confirming that info, the CSR ordered a replacement 622, it arrived within a week, and the HDMI connection is now working on that replacement.
It felt like the replacement's HDMI connection was different and it makes me wonder if they have started putting better connectors on that receiver.