TRy doing a signal search with the Rabbitears search map:
RabbitEars.Info
This will give us an idea of potential problems.
You may be near the "digital cliff" with this channel.
Looks like I am near the "digital cliff" per this website. My CW channel IS listed as POOR and if the signal does drop at 9:00 for this channel, then it could then change to BAD. It doesn't explain why Dish shows the signal strength of 100% for CBS for those times I got the same error codes at 9:00.