Thanks for keeping in touch and providing the additional information.
In this case, It's best to reach out to ATT&T TV to get the channel going on your Roku. They can resolve the error you are having with the channel login. Please be noted that Roku doesn't manage channel logins or authentication and many channels on Roku are developed and maintained by the channel provider themselves.
I have a Starz subscription, however it is not giving me an option to log in under the Stars app. It previously was logged in under an old roommate. How can I use my own account that I did not purchase thru Roku
Try removing the channel from the Roku home screen by navigating to the channel tile, pressing the * key on your remote, and choosing 'Remove channel'. Then restart your device from Settings>System>System restart. Once your player starts up again, add the channel back once more. Sign-in into the channel with your Starz account, you will find the login option on the top right corner. If the issue still persists, we suggest you reach out to the providers directly.
Are you trying to access through the Starz standalone channel or through The Roku Channel?
For more information about that channel's authentication, you'll want to contact Starz support directly to inquire further. Many channels on Roku are developed and maintained by the channel provider themselves.
This is not a solution to the persons problem. You answered with how starz is supposed to work. Its obviously not working how its supposed to work or that person would not be on here looking for help. My starz channel is doing the same thing. It kicked me out like every other channel does when they feel like it. Only this time when you go to the top right corner and click on the gear icon, you only have one choice, start a 7 day trial. If it was working correctly then I would do as your answer states and login with my tv providers information, but its not working correctly. Just another day with multiple things having issues.. I'm finding these kind of issues very routine. Yeah, they (the little kids) all wanted to cut the cord, but doing this has caused lots of other issues. One being there is always something not working right. Like everything that has to do with phones, tablets, streaming, apps, google, roku, actually even all the **bleep** we get sold from china as well. Gone are the days of things working right out of the box the whole time you're using it, everytime you use it. Today's things/items are designed to sometimes work intermittently.
Please be advised that Starz through The Roku Channel doesn't have an option to log in since it automatically uses your Roku account information. We would recommend making sure you are accessing the standalone Starz channel so you can log in to your existing Starz account or TV provider.
Are you telling us that we can no longer use Roku to get to our Starz accounts that we pay for through our tv providers. And if we don’t have a smart tv that has that app we are out of luck? What kind of nonsense is this, since I’m paying for Starz and can only view it in real time? And you specifically do not provide customer service for anything but sales? I don’t get it. Really I don’t.
Can you please clarify how you are trying to access your Starz subscription? Are you trying to access the content directly through the channel provider or are you accessing it through your TV provider's channel?
With more detailed information, we will be able to assist you further.