I have been using a Roamio OTA now for about 18 months. Lately I have been noticing 2 channels that have significant pixelation. Signal strength is 100%. My first thought was maybe a bad connection somewhere but everything checks out. I disconnect my coax from the Roamio and plugged it directly into the TV and those channels are perfectly fine with no pixelation. The problem always occurs on RF3 and RF13 (no problems with RF7, RF11, etc.) I'm getting RS Uncorrected values in the thousands and SNR is steady at 29db. Could this be a sign of a bad tuner?