Tivo can't display certain HD channels that the cablebox can

Does Tivo require a stronger signal then a traditional cablebox? Here is my issue. I have had lots of problems with my cable company that has been going on for a while (poor signal, especially HD channels). For about the past month, they've got it to a point where I get all of my channels without a problem when going through my cablebox. But with my Tivo Roamio, I had problems with several HD channels - always the same HD channels (about 6 of them). Because of the overall weak signal issues I've had in the past, the cable company did install an amplifier. There's also a splitter on the line. I've tested with and without the splitter as well as with and without the amplifier. The conclusion is the cablebox is able to display those channels without problem while the Tivo cannot (either no picture and the error message OR a very pixilated channel). I've used the signal strength tool on Tivo and it does same those channels are low.

Does anyone know if a Tivo typically requires a stronger signal then that needed by a cablebox. Or has anyone had a similar issue or have any tips or testing steps I can do. The cable company is pretty much at the point where they are saying everything fine because it works just fine with the cablebox.

Thanks