Hello, @Hardcore09.
Welcome to the Rogers Community Forums! 🙂
I appreciate posting your query in the Community. It surely sounds strange that you can log into the NHL app on your iPhone but not on your computer or the Apple TV.
It could be related to your purchase; have you performed In-app purchase on your iPhone? If yes, please follow the instructions to link your In-app purchase.
If not, please provide us with more details about the purchase.
Cheers,
RogersMoin