I recently moved to the US and had Spectrum installed, and I was wondering why channels, even HD ones, looked pretty crappy on my new 4K TV. After messing with the settings on the box, it seems the highest it can output is 1080i, not even 1080p. How can that be true in 2017?
It's all the bandwidth that's available on cable and very little programming is true HD to begin with.
Best bet is a Blu ray player or one of the streaming video IPTV sources.
Put an antenna on your set and see how much better live network sports are.
BTW, 4k tv is a total joke on anything smaller than a 40 or 50" set, it's a marketting ploy with no support