Node.js version

22.19.0

jsdom version

27.0.0

Minimal reproduction case

I don't have a specific test case, but if you need one I can spend the extra few days to come up with one

How does similar code behave in browsers?

This is not a browser issue, but a testing issue

What is the problem?

Attempting to upgrade from 27.0.0 to 27.0.1 is breaking a bunch of our unit tests due to timeout issues. In upgrading from 26.x to 27.0.0, I already had to quadruple the timeout value for one of our tests. Now it seems that more of them are too slow due to 27.0.1. I don't have specifics about what APIs have slowed down, but they clearly have.

We are using @testing-library/react