Welcome to the Roku Community, @Randomuser222!
Thanks for reaching out here. We'd be happy to help you access Hulu Live TV on your Roku Ultra.
Before we proceed, may we know if your subscription is directly purchased from Hulu? If so, have you tried directly accessing it through the standalone app?
Furthermore, how are you accessing it on your other device? Is it via the Live TV on The Roku Channel or the Live TV Guide icon?
With more detailed information, we will be able to assist you further.
Warm regards,
Carly
Carly Y.
Roku Community Moderator