Spectrum TV app on TCL/Roku - TWC TV and Apps

I purchased a new TCL/Roku TV last week for a cottage 100 miles from my home. I have an excellent WiFi connection through a Verizon Jetpack hotspot..When I try to login to the Spectrum app, I'm told it will only work in my home. I've installed, uninstalled and reinstalled the app a dozen times with no luck. Ironically, my iPad using the Spectrum app works perfectly. I've called Customer Service and gotten nowhere.

This question is about "Spectrum TV app on TCL/Roku", with Time Warner Cable TV and apps.