There is a bug when rendering nested `PanelBarItem` components into a `PanelBar`. This error began in version 8.0 and still exists in 8.2.0.

In the linked example sandbox, you can see that I am rendering an empty array of children and it causes an error. This used to not cause any issues.

An empty array is needed because we render some `PanelBarItems` that come from an AJAX query and so the children starts off as an empty array until the requests completes.

code sandbox example of bug

Thank you,

Ryan