Is Britbox the only channel you are having this problem with?
If a problem is confined to only specific channels it may be that the channel installation has become corrupted and ought to be reinstalled.
Remove/reinstall procedure:
1. Highlight channel on home screen.
2. Press * key and choose Remove channel option.
3. IMPORTANT- DON'T SKIP:
From home screen, Settings > System > System restart. This assures no remnant of the old installation remains in the Roku's memory so you get a complete reinstall. It may or may not make a difference, depending on what's causing your problem, but it's worth doing.
4. Reinstall the channel.
5. If channel requires a login, you may need to log in anew.
Note that a reinstalled station gets added to the bottom of the channel grid on the Roku home page.
Roku Community Streaming Expert
I am not a Roku employee, only a user like you.
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