Tablo HDMI has no video on one channel only

Tablo unit has approx 18 channels. All but one fails to pull in Video. Guide shows up, audio present sometimes. Multiple resets and factory default resets, HDMI cable switch out and two different OAT. Signal strength on problem channel is strong.

Signal strength is not signal quality. Sometines an amplifier helps as does better antenna direction or better antenna.

Does this channel look normal not using the Tablo and any errors on the Tablo like weak signal or anything like that?

For best reception on the HDMI model, I had to turn any gain all the way down, seems to much, knocked out about 8-10 of my channels as I kept turning up the gain. Soon as I turned it all the way down, my channels are back.