I have a Britbox subscription which works on my Roku devices but does not work on my smart tv with Roku. It will only let me view if I subscribe again on that device. Any suggestions?
If your subscription is through Roku, the subscription is tied to your Roku account. Is your Roku TV linked to the same Roku account as your other Rokus, as identified by the email address used for each account? Settings > System > About on each Roku will show you.