Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
Roku just provides the platform on which the channel apps run. The apps are created and maintained by the channels themselves, in this case by Apple. Questions about how the Apple app and its controls and operation work should be directed to Apple.
Although, if you're lucky, someone familiar with the Apple Roku app may be able to provide some advice..
Roku Streaming Stick +, 3810X, Ser YH0059427035, wifi - Samsung UN55ES6100
Roku Streaming Stick, 3600X, Ser 5S56D8240827, wifi - JVC EM37T