DropDownList filtering grouped data throws error when the list is scrolled

[gdenchevprog]

Bug report

Grouped DropDownList that is scrolled down, throws an error when you attempt to apply a filter that returns no values.

Reproduction of the problem

1. Open the Dojo - https://dojo.telerik.com/@sspasova/ImETEGuK
2. Open the DropDownList popup
3. Scroll down in the list
4. Apply a filter that returns no values (for example type "5" in the filter input).

Current behavior

An error is thrown in the console.

Expected/desired behavior

No error should be thrown.

Environment

• Kendo UI version: 2023.3.1114
• jQuery version: 3.4.1
• Browser: [all]

[iordanGrancharov]

Not reproducible with latest Kendo version (2025.2.520).