To demonstrate the issue:

npm install

# Verify that version 14 of user-event is installed. 
npm ls @testing-library/user-event

# Launch storybook
npm run storybook

The story that opens should have the input focused (with a cursor) and "foo" should be written inside.

Instead, it will look focused (have a dark border), not not have a flashing cursor, and the text is not pasted.

To see the behavior in V13, add this to the package.json:

"overrides": {
  "@testing-library/user-event": "13.5.0"
}

Then npm install, comment out userEvent.paste('foo') in Input.stories.tsx (the api of .paste() has changed) and restart storybook npm run storybook. You'll see that the input is properly focused now.