With new Roku devices starting at $25 when on sale, a Roku seems like a smarter and more veritile choice for many things than any brand smart TV. Or at least that thought is something to consider...
I have never owned any brand of "smart" TV, and don't intend to. I have a Roku 2 Internet device, with the Roku Spectrum TV app, connected to my Insignia 32" flat screen and have had no issues with it. From what I have read here about the "smart" TVs from Samsung, TCL, et al., I get the impression that the streaming TV apps included with these sets do not always work well. Given the problems people have had with TCL and other brands of "smart" televisions using this app, I'd bypass it and use a standalone Roku Internet device to receive local TV. These devices do have the Spectrum Roku app preinstalled; it seems to work very well. (The app on my Roku 2 has worked flawlessly since I installed the device on my TV over one year ago.)
If you want to continue to use the installed Spectrum TV app with your "smart" TV, I would look first to see if there are any menu options in your TV's "system" or "settings" menu (if it has one) to update that app, or if the app updates itself automatically as does the Roku software. If not, bypass the stock app and use a standalone Roku device, as I mentioned. It will save you a lot of aggravation.
I've personally never had an issue with using the Spectrum TV app on any one of 3 Roku devices in my house, including a Sharp Roku tv. Samsung seems to have screwed up their software to a point that the app on their smart tvs is a bit of an adventure.