Sling Blue not getting National Geographic and Fox News on TVE. They are available on Sling App but not TVE! Anyone else having this problem? How do I delete TVE and reinstall? Maybe that's my problem!
Did you ever solve this? I have the same issue with Sling Blue and CNN/NewsNation, though I do get Fox News.
Instead of replying to a two+ year old post, you'll probably get a faster response if you post your issue in the Sling TV topic, or create a new post in the TV Everywhere section.
Meanwhile, here are some TVE Troubleshooting tips that may help you.
And it looks like Sling TV doesn't allow access to CNN Channels Support - TV Everywhere Availability
When you go to their website https://go.cnn.com/ and try to login with Sling TV, it's not listed as a provider.