One of my clients has just shifted house and took their Spark fibre + landline (VIA ONT) along to the new address. I have them setup with noip (Dynamic DNS) and DNS4me so that their Roku box can access overseas content. All has been fine for years, until their shift. Their HG659B reports an IPV4 address of 100.65.239.XXX (a non-routable IP) which is sent to noip.com but this isn't their real IP which happens to be 203.211.74.XXX when checked at whatismyip.com. Obviously DNS4Me refuses to accept this address in their IP Access zones so their service fails. 

This leads me to believe that Spark have started to use CGNAT on new connections? Does anyone know what's happening here?