Maximizing in the official "Adding items to a predefined layout" CodePen doesn't work

[AlexErrant]

Current behavior

1. Go to the CodePen: https://codepen.io/pbklink/pen/dyWJNNm Note that this is the codepen linked in the v2 docs.
2. Hover over the right corner of any window until you get a tooltip for the Maximize button. (The Maximize button blends into the background - the CSS is not great, but not the point of this issue.)
3. Click
4. Scroll down. Observe that the other panel is visible... which is weird.

Expected behavior:
If one panel is maximized, the other window should not be visible. Also, no scrolling should be possible

Codepen example:
https://codepen.io/pbklink/pen/dyWJNNm

[ratatoeskr666]

Yes... I can confirm. Maximizing seems to be broken (V2.6.0)
The 'maximised' event is also not being triggered:

 container.addEventListener('maximised', () => this.onContainerMaximizes(container)); // Not being called :( 

[ratatoeskr666]

I found out the workaround (maybe the issue is correlated to the broken CSS):

.lm_root {
    overflow: hidden;
}

The maximized container is being prepended under the ground item (root) by design. Everything else is moved outside the frame (and the original stack is being replaced by a placeholder).
The implementation requires the root to be overflow: hidden so that the rest is no longer visible