I'm having trouble adding a non-certified channel to my device for testing purposes. I've already enabled it for all countries, including "Rest of the world". But when I try to add it I'm getting an error message stating "The channel code provided is associated with a channel not available in your region". Then I tried to reach Support (https://developer.roku.com/contact) and filled out the form, but was unable to submit it. The error dialogue message didn't say much, apart from the generic statement "Oops! Something went wrong, please try again". Status code: 400.
Re: Troubleshooting: Adding a non-certified channel
Roku has an issue with their system since around last September with adding Private Channels. I have been working with them to fix the issue and unfortunately they did implement a fix but it didn't fix the issue for all users. Try adding the channel using the original vanity code. If that still doesn't work you could try raising the issue with their developer support team at email@example.com but they don't really want to support Private Channels anymore and will try to get you to make it Public. Good luck