When doing network troubleshooting they will try and get you to factory reset the home router they gave you, which enables IPv6 and bricks their end and has to get escalated.
But they provide fibre to the premises and aren't supporting BT, so it's not all bad.
I was CGNAT at first, but their implementation breaks consoles as well, so you can complain about your XBox not working and they give you a static IP.
So do they have to order new routers every time you do this? Hopefully after you have destroyed all of their routers, they will eventually buy new ones that are actually compatible with IPv6 so just keep doing it. /s
But it requires an engineer visit to talk to their NOC so I can be without internet for a couple of days.
Sucks.