### Bug report

When integrating components into the ToolBar by using the TemplateId() or TemplateView() options, the ToClientTemplate() option throws a client-side error "SyntaxError: Failed to execute 'appendChild' on 'Node': Unexpected token '<'".

When the component is added to the template without the ToClientTemplate() option, the component is rendered as expected in the ToolBar.

### Reproduction of the problem

A REPL sample for reproduction: https://netcorerepl.telerik.com/cTYqlaPG12psetl157

Remove the ToClientTemplate() option to observe how the DropDownList is rendered as expected.

### Expected/desired behavior

When using an external Kendo UI Template, any nested components must be defined with the ToClientTemplate() option.

### Environment

* **Telerik UI for ASP.NET Core version: 2025.2.520
* **jQuery version: 3.7.1
* **Browser: [all]