Bug report
Еxpanding/collapsing nested panels collapse the parent panel as well

Reproduction of the problem

Can be replicated in the following Dojo:

https://dojo.telerik.com/EboZUXif

Current behavior
Collapsing or expanding a nested panel collapses/expands the parent panel

Expected/desired behavior
Collapsing/expanding the child panel shall not collapse/expand the parent

Environment
Kendo UI version: 2021.1.119
Browser: [all]