node:test and async register hooks broken after 24.12.0

Version

24.12.0

Platform

Darwin MSK-G4LQ6YF03T.local 24.6.0 Darwin Kernel Version 24.6.0: Mon Jan 19 21:59:23 PST 2026; root:xnu-11417.140.69.708.3~1/RELEASE_ARM64_T6030 arm64

Subsystem

No response

What steps will reproduce the bug?

Context

Hi, I have small TS loader for Node.js:
https://github.com/krutoo/ts-loader

I use it like:

npm i ts-loader@npm:@krutoo/ts-loader
node --import ts-loader ./test.ts

You can see real example with issue here:
https://github.com/krutoo/utils/pull/212

Under the hood loader just runs http server in first process and registers hooks by module.register

Hooks uses fetch to request server to complie modules

Problem

After upgrade to Node.js 24.12.0 server don't answer any requests, even from browser, there is tab that waits for response

I don't have skills to figure out the cause myself.

Tried log some steps, seems the server isn't accepting any incoming requests at all.

Even though the server itself has definitely been created, has taken over the port, and is accepting messages.

Can someone help to understand cause of this behavior?

How often does it reproduce? Is there a required condition?

Clone this repo and branch:
https://github.com/krutoo/utils/tree/tsimp-replaced

Then:

nvm install 24.12.0

npm use 24.12.0

npm i

npm run test

What is the expected behavior? Why is that the expected behavior?

Don't have enough skills to understand it is a bug or new behavior of async loader hooks

What do you see instead?

Tests freezes

Additional information

No response

Reproduce the freeze with Node.js 24.12.0 using the linked krutoo/utils tsimp-replaced branch and its npm test command, then compare behavior with the loader described in krutoo/ts-loader. Investigate the module.register async hooks and fetch-based server requests; done means the test suite completes and the loader server responds to requests after the upgrade.