Missing toString method passing an object as kendo.Observable

[aleksandarevangelatov]

Bug report

If an object has an overridden toString method and is passed as a kendo.Observable the toString method of the object is not passed. This is a regression introduced with v2020.3.1023.

Reproduction of the problem

1. Run this dojo
2. The overriden toString method is not available

Expected/desired behavior

The custom toString method should be passed, as in v2020.3.915: dojo

Environment

• Kendo UI version: 2021.1.224
• Browser: [all]