When an <iframe /> DOM Node is moved to a different place in the tree, Chrome triggers a reload. That reload does not notify event handlers registered via onLoad=. In other words:

• If there is an event handler registered via onLoad={myCallback}, it will not be fired.
• If there is an event handler registered via iframe.addEventListener("load", myCallback, false), it will be fired.

React version: 16.13.1

Steps To Reproduce

Open a code example below and move the iframe down using arrow button next to it.

https://codesandbox.io/s/serverless-surf-k1ypg?file=/src/App.js

The current behavior

The iframe does not say "Initialized" anymore.

The expected behavior

The iframe should say "Initialized".

Other notes

If you move setIframeContent(e.currentTarget); to nativeLoad and repeat the steps above, it works as expected. The bug does not occur in Firefox.