Sometimes there's something about the Roku account that you're linking the device to that's causing a problem. Assuming you already had a Roku account and you're linking the TV to that existing account you might want to try to create a new Roku account and link to that to see what happens. I assume you're in the UK given the channels you mentioned. If you somehow created a US account (often through no fault of your own), that can cause issues, although I don't think insufficient storage is one of them. Also, if you imported the TV that could be an issue.
If it's a new account and you're having that problem it may be best to return the TV. I don't have much patience with brand new devices that don't work properly.
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