I tried to add this to my original post but I couldn't so I'm posting it again since it took so long to find the answer. I think the confusion came from Roku's instructions, at least when the paid Newsmax+ started. They said to use the Roku credentials period but when this info said if you paid through Newsmax.com to use the credentials for them. I hoe this helps for anyone that may still be having trouble. See below!
I finally found an answer to not being able to watch Newsmax+ on multiple TVs. This is the link on Newsmax.com. If you pay through Roku it will tell you what to do, and if you paid through Newsmax.com, it will also say what to do. I paid through Newsmax.com and did what it said and it came up and worked. Good luck. It only took right at a year to find this answer. Link below!
https://support.newsmaxplus.com/hc/en-us/articles/10870544310940-How-to-Watch-Via-Roku
