Trying to watch a show on Paramount+ through a web browser via The Roku Channel and it's telling me I have to subscribe but it's showing I am, any clue why?
Since you’re asking on a Roku forum, I’m guessing you pay via Roku? If so, whenever you use a platform payment system (Roku, Apple, Android, Amazon…) it is frequently somewhere between tricky and impossible to use your subscription elsewhere. This is one of the reasons many people here will tell you to subscribe directly with the content companies.
Yes I paid through Roku since they had a deal for both.
When you subscribe to paid premium channels through Roku you typically can only view them on actual Roku equipment, many (most? all?) of them via The Roku Channel.
The Roku Channel, when viewed through other means (web version, Roku Channel app on non-Roku devices), typically provides access only to the content of The Roku Channel itself, not provide premiums accessed through The Roku Channel on actual Roku hardware.
As mentioned by @Strega2, if you wish to view premium subscriptions on platforms other than Roku, you should subscribe to them directly on their website. Then you will be able to log in and view them on all platforms they support, either on their website or on their dedicated apps for each platform.