Have you tried running the diagnostic test? You can find it under Settings > Run diagnostics test. Could you post back the results?
Did you ever get your poor quality TV issue on Fetch resolved?
I have just bought a new TV and I can see a big difference between FTA channels on Fetch to directly on the TV.
I am thinking of ditching Fetch TV for a service that has a better quality box.
It's weird for you that your Fetch TV is showing what can only be described as a poor signal.
When it comes to Streamed channels, the quality of the connection is what matters. Most streamed channels require 4mbps for a clear HD picture.
I have a mighty with my video settings on the Fetch set to 4K (2160p/60) and the picture is fine for me.
FTA looks terrible on normal channels so I only watch HD channels if anything these days anyway.
Try doing a FTA channel test too, could be just the antenna needs a little repositioning.