I believe the issue isn't with TCM (well it is in a way), it's with Adobe. TCM uses something called Adobe Primetime Authentication service to verify your cable/sat subscription. When TCM goes "redirecting", it's sending you to a site called entitlement.auth.adobe.com. If they don't reply, you're SOL. I'm having the same problem on one of my tablets running the Watch TCM app. Oddly enough, it works fine on my phone or a different tablet, all on the same LAN, same router, same everything.
If you want, you can try complaining to email@example.com. That can't be any worse than complaining to TCM, who obviously don't give a hoot whether anyone can watch their content or not.
HEY TCM - FIX THIS!!!