Bug report

Grid's items are not correctly calculated when a group is expanded and groupPaging is set to "true".

Reproduction of the problem

1. Open this Dojo and run it
2. Expand the "Assistant Sales Agent" group.
3. Expand the "Assistant Sales Representative" group

Current behavior

On the expand of the "Assistant Sales Agent" group, the footer displays the following:

On the expand of the "Assistant Sales Representative" group, the footer displays:

The number of the displayed items is incorrectly calculated

Expected/desired behavior

The number of the displayed items should be calculated based on the number of the rows inside the opened groups

Environment

• Kendo UI version: 2020.2.617
• jQuery version: x.y
• Browser: [all]