This is strange. Trying to logon to the 2D account page for Broadband from a 2D UFB account and I get this

https://secure.2degreesbroadband.co.nz/login

CloudFront attempted to establish a connection with the origin, but either the attempt failed or the origin closed the connection. We can't connect to the server for this app or website at this time. There might be too much traffic or a configuration error. Try again later, or contact the app or website owner.
If you provide content to customers through CloudFront, you can find steps to troubleshoot and help prevent this error by reviewing the CloudFront documentation.

Generated by cloudfront (CloudFront) Request ID: a0k5wxqrXHgA6m-gNthQQHFrRNSA8LS4ZdgINSVvz6bXT_Vi8ccFLQ==

It happens on my phone on WiFi also (just times out) but as soon as I switch to LTE it's okay.

And other pages are fine like this

https://www.2degrees.nz/2d/mobile/common/login/login.jsp

But the URL is quite different so a different server farm?