I have also been a customer from the very beginning. I am having the same problem and they finally told me that Roku and pp were in talks and that they couldn't fix it. So after 2 months and them charging me for a live channel that doesn't work which they can't fix or won't fix. Really bad customer service. Also, how do they add the live channel for the people just signing up? Is it just with Roku that it doesn't work? If that's the case maybe they need to find some better IT people to solve this problem. If I were to cancel my subscription and add it again with the live channel with my Roku, would I get the live channel at the more expensive price? Or are they just not able to do the live channel with the Roku at all? If that's the case they need to make that known so that people that use Roku are aware of this.
Live TV works for the vast majority of P+ subscribers (non-Essential plans) using the P+ app on Roku.
Many of the problems arise from those that subscribe through Roku/Roku Pay (instead of directly or elsewhere), and then cannot remove/restart/reinstall the P+ to fix issues with the app.
If you haven't already done the in-app local station check, do so: Open P+/Profile/Menu/Settings/Live TV/Check Location.
Otherwise, as stated before, Paramount is entirely responsible for the functionality/behavior of the P+ app, and you'll need to continue with their support.