Duplicate read request is sent for cascading DropDownList or ComboBox with enabled filtering

[nelito987]

Bug report

When filtering is performed in the parent widget and an item is selected, duplicate read request are sent to the remote end point for the child widget data.

Reproduction of the problem

1. Open the Dojo
2. In the parent DropDownList search "be" and select "Beverages"

Current behavior

Two requests are sent to the 'Products' DropDownList read end point.

Expected/desired behavior

There should be a single request for reading the widget`s data.

The issue is a regression since 2019 R3 SP1 (2019.3.1023)

Environment

• Kendo UI version: 2021.3.1109
• Browser: [all ]