Problem 1 - set the receiver to AV1, then go into the receiver Device on the harmony website and click "confirm IR language". It will tell you to connect the harmony and then push 3 or 4 buttons on the receiver remote and it will select the proper IR language so that it works with AV1.

Problem 2 - first go into Device mode and see if any of the Input commands get you directly to the DVI input. Even if the original remote didn't have such a command it may exist. You're only checking the activity input selection - you need to go into the TV device and "adjust inputs". Make sure you answer all the questions correctly and the list of inputs matches the TV exactly. That's where it determines how to change to the "DVI" input you selected in the activity. My guess is it's setup to send the InputDVI command followed by the "1" command. Fix it there and it will work in the activity.