Use IPv6.

I’ll give it a shot.

In the past, before the internet existed, homes were connected to the national phone system. The national phone system is a bunch of interconnected electric lines that are designed to transport electricity in the frequencies used for speech / sound.

When internet became a thing, people needed electric lines to transport data from their internet providers to their home. Instead of building new electric lines, which would be very expensive, tech companies created a technique called “modem”.

A modem transforms computer data into sound data, which can travel through phone lines. Once the sound data reaches the internet provider, another modem turns it back into computer data.

That’s a pretty strange statement from your ISP. You should be able to configure your router to allow traffic to whatever IPv6 address that you want.

Since I don’t see it mentioned in this thread, wouldn’t enabling IPv6 allow you to do what you want?