Tvheadend

I'm totally new at all of this, so any help is greatly appreciated. I did exhaustive Google and Youtube searching (unsuccessfully) before resorting to a forum post ...

I have two USB devices on hand -- Hauppauge WinTV-HVR-950Q and the Xbox TV Tuner. I'm having the same issues with both devices.

When I plug into my RasPi4 with Librelec, install everything, run the scan with the default muxes I get about half the channels that I should get. This is old school QAM cable (plugs right into the wall, no cable box or anything).

When I plug into my Windows 10 PC and use WinTV software (downloaded from the mfg), I get all 100 or so channels. I can also use NextPVR with something I believe was called SoftPVR and get the same channel lineups (SoftPVR somehow incorporates things from WinTV to help find all the channels). However, I'd like to use TVHeadEnd and my RasPi instead of my PC. I assume I need to manually add muxes or something, but I have no idea how to do it. I've looked for manuals. I also don't know what relevant information could be used from the other software devices to help in this process. How do I find the relevant info to create the mux.

For example, in TVH I don't get channel 33.1 for some reason. On WinTV is recognizes it as 33.1 and assigns number "2331" next to it. In NextPVR it simply says Freq: 60 SID:1

Is any of that info helpful to me in TVH? If not, what can I do? It's a very small, local cable provider for a town of less than 10,000 people, so I don't know if I'll be able to find frequencies or muxes or whatever on the web.

Thanks so much, this has been frustrating!