Channels DVR TVE has nothing to do with other apps like AppleTV, etc.
If you can authenticate using your browser at a Network Live website that your Provider gives you TVE access to using your Provider credentials, but are having issues using Channels DVR TVE authenticating with it, follow the TVE Troubleshooting tips
Sorry, but there are hundreds of posts about this on this forum, and we get tired of repeating ourselves constantly. Channels DVR TVE uses the network live streaming websites, not an app or your provider streaming website. Many providers have issues with their TVE auth servers in providing this service to their users and timeout or give errors when trying to authenticate.
You can also see issues raised by users for CDVR TVE access in this section TV Everywhere - Channels Community of the Community Forum (which isn't an Official Support Forum)