Localhost relay does not support dual-mode sockets

Your Windows build number: (Type ver at a Windows Command Prompt)

Microsoft Windows [Version 10.0.19551.1005]

What you're doing and what's happening:

I am trying to start-up a webserver and have it listen on a specific port. Then when I try to reach this website using a service like localtest.me it says it's unreachable, this is specifically happening when I try to run shadow-cljs on WSL2. If I run it on a WSL distro it works fine. After some talking with the author of that package I was able to boil down a reproducible issue to:

1. In a fresh instance of Ubuntu with WSL2 enabled run nc :: 8080 -l
2. Try to connect to nc, on Windows with any browser, at the address 127.0.0.1:8080.

What's wrong / what should be happening instead:

When opening up a server and telling it to listen on '::' and port 8080, the server becomes unreachable on the Windows side when trying to access it through a browser on 127.0.0.1:8080. However, the server is reachable through the browser when accessing it through localhost:8080. This workflow used to work on WSL1. I have tested this on a multitude of ports and it never works.

Additionally, this works fine if I use nc 0.0.0.0 8080 -l instead. It is reachable by browser on 127.0.0.1 and localhost.

No source files or tests are named. Start by reproducing the issue with WSL2 Ubuntu using nc :: 8080 -l and compare it with nc 0.0.0.0 8080 -l, then trace the localhost relay and dual-mode socket handling. Done means a server bound to :: on port 8080 is reachable from Windows through both 127.0.0.1:8080 and localhost:8080.