> That led to the discovery that 4.1 virtual is 108.1 real, and so on.
> Just cant find the real channel for 9.1 (yet).
If 9.1 is at 108.xx you will never be able to tune it, because 108 real is virtualizing to 4 because the PSIP is set incorrectly by the cableco or is corrupted i.e. Instead of just the sub-channels virtualizing, the major channel is virtualizing all 128.xx sub-channels to 4.xx subchannels. When this happens you lose all the real 108 sub-channels. When 4.** is not a valid channel, it defaults to 4.1.
FWIW, this is not an uncommon event, and Comcast does not consider it to be a network problem.
Comcast's STBs don't use PSIPs, they use the virtual map in memory, so PSIPs are a total no-care for them. I wish you better luck than I've ever had trying to get any kind of sensible response from them, the repeated recommendation is rescan because everything works with our STBs. I have not yet met a tech who has the slightest clue about what a PSIP is.