I second that.
As to weird, it gets moreso. ATSC tuner outputs over coax are fought tooth and nail by providers fearful that "in the clear" digital signals will be immediately put on the internet, cutting their sales and profits.
It's a dilemma.
PS- TheKrell beat me to it. ATSC OTA is all MPEG-2, which I believe is always included in MPEG-4 chipsets, but would require conversion, as noted. By the time ATSC OTA is updated to include MPEG-4 or other options, OTA may be dead, now that we know of the hostility the FCC has for it. Destroying HD by requiring multi-channel multi-casting will end OTA as we know it, and quickly.
Anyone having similar problems should certainly try the cable channel option.