When I try to access Fox News I get asked repeatedly to sign on with my service provider (Direc TV) and enter a code shown on my screen. Then (usually) I am allowed to see current Fox news reports. Otherwise I get shunted onto recent, but not real-time, reporting.
As of today, Roku is no longer offering me a list of service providers to choose from or any other way to identify my provider. So I am now effectively cut off from access to real-time Fox reporting.
If I were to run into a similar problem with any channel the first thing I would try would be to reload the channel app.
If the problem persists at this point, it typically means the current version of the channel app has a problem that must be addressed by the channel itself as they are the ones that create the Roku-compatible version of their app and provide it to Roku.