Error is thrown when a second grouping is performed while the first grouping is still loading

[nelito987]

Bug report

When the user adds a group in the Grid and try to add a second group immediately, while the first grouping is still loading, then an error is thron in the console.

Reproduction of the problem

1. Open the dojo - https://dojo.telerik.com/CvYRPILM
2. Group by 'Freight' and immediately try to group by another field. Before the grid data source reloads from the first grouping, take another column to be grouped and select it without releasing it in the grouping space.
3. Once the first group has been loaded, release the second group

Note: you can try setting the n browser Network throttling to Slow 4G to easily reproduce the issue

Current behavior

Error: kendo.all.js:60347 Uncaught TypeError: Cannot read properties of undefined (reading 'left') is thrown and the Grid freezes

Expected/desired behavior

There should be no error in the console and the Grid should not freeze

The issue is a regression starting with 2023.1.314

Environment

• Kendo UI version: 2024.4.1112
• Browser: [all ]