Cloudflare has had some issues the past week or two, but it's doubtful this is related.
Often when something like this happens, it requires either a CAPTCHA or password reset with your cable/OTT provider.
First, try logging in to your account page with your provider. If there are password reset issues, that's where they'd show up. If you can successfully log in there, then proceed.
Second, after you can access your account management page with your cable/OTT provider, now try to access a supported TVE network website. (For instance, if your provider grants you access to NBCUniversal feeds, try https://nbc.com/live – although that isn't working at the moment for me, so maybe this is an Internet/backbone issue.)
Third, after you have successfully used your credentials to both access your account management page, and successfully login on a network's website, only then should you attempt to rescan or stream from within Channels. If you had to change/reset your password as part of the previous two steps, then you can either delete your TVE source and re-add it, or you can inform the DVR of your new password:
If problems persist, then it could be likely that it's an issue on their end, and not something you can fix yourself.