It is common to refer to CGNAT but I believe the reality is that the solution is in reality 464XLAT. Cross translation of IPv4 to IPv6 & back to IPv4 which is a bit of an evolution over CGNAT. The dual stack solution seems to also take this to a hybrid routing solution depending upon the type of traffic. 

The goal is to move forward to IPv6 which would resolve the limitations of IPv4 and would probably eliminate a considerable amount of complexity. 

well i wish they understood why this happens and how to prevent it. the twitter guy supposedly kicked me out from the tower and when i turned it back on i got an ipv4 again, but last time i did the same as well (although i left it off overnight)

Go to https://whatismyipaddress.com and allow the location and it should provide both the IPv6 & IPv4 addresses from an external perspective. Interesting to see. They have a speed test tool too. It just reported 357.4 down & 43.9 upload speed. A bit of a surprise but sourcing out of Atlanta so maybe not. 

i'm aware of how to get my ip addresses , but that doesn't help to determine why i'm unable to get them whenever it's down.

I know just sharing that as it provides both the IPv6 and IPv4 and if one or the other was not resolving that might be good to know. I have seen times when there is clearly both cellular signals and clients that have no internet notifications. If i just statically asking the DNS servers I have seen that to be a fix when the DNS is nor resolving through the default DNS via the gateway IP.