Trouble signing into an app

Weather Channel app won't let me sign in. It just offers me a 7 day free trial with 2 options. One to start the free trial and one to sign in if you already have a subscription. I select the latter because I have a subscription, enter my email and password for the subscription. It takes me back to the original 7 day free trial page with the same two options and responds with, "you're all set. Your Roku account already has an active yearly subscription and you can start watching right away." But I can't because it's a loop. Sign in button, enter email and password and it's back to the message, lather, rinse, repeat.