Paramount+ on Roku stuck on a Login Loop

When this channel is one for which you have a premium subscription through Roku, there will be a "Manage subscription" option instead of a "Remove channel" option. You can click this and follow the prompts to prevent further payments, but under Roku's current coding you will not be able to remove the channel through the Roku interface until the pre-paid subscription expires.

While the subscription is in force you can use the official Roku remote app on an Android/iOS phone/tablet to remove the channel from your account.

At the bottom of the app's Home screen, click "Devices" and connect to one of them if not connected already.   On the Devices page, click on "Apps on Roku" and find the channel you want to remove.  Click AND HOLD on the channel to be presented with options to Launch the channel on your Roku, or to Remove the channel.  (A quick click will instead bring up the remote control functions.)

Now Restart the Roku to remove all traces of this channel from the Roku's memory cache.

This will remove the channel from your Roku account and allow you to reinstall it in the hope of fixing your current problem, but it will NOT cancel the paid subscription to that channel if there is one.

Having the same issue, going to do a factory reset . To get rid of others info and apps that they put on my Roku device and re down load my own paramount plus.

You're stuck in a common issue where a Roku-billed Paramount+ subscription doesn't work properly with the standalone Paramount+ app. If you subscribed through The Roku Channel, you can only stream Paramount+ content within that channel — not the standalone app. Since you've already canceled your subscription, wait for the billing period to fully end, then remove the Paramount+ app from Roku (press * > Remove Channel), restart your Roku, and reinstall it if needed. If you want to use the app directly going forward, create a new Paramount+ account once your Roku billing is fully disconnected. For now, stick to The Roku Channel if that's how you signed up.

Try logging out from all devices at paramountplus.com/account, then remove the Paramount+ app from Roku (press * on the remote), restart your Roku, and reinstall the app. That usually clears the login loop.

Nightmare and still going on.