Hi Kaya,

Currently, a fellow colleague of mine has been assigned to provide a fix candidate for the issue that was initially reported for the CheckBox TagHelper.

As for the RadioGroup TagHelper, in order to add arbitrary HTML attributes explicitly to each of the items, I would personally recommend utilizing the "html-attributes" TagHelper attribute. For example:

@{
    var attributes = new Dictionary<string, object>
    {
        {"data-bind", "checked:SomeValue"}
    };
}

<kendo-radiogroup name="BoolTest">
    <kendo-radiogroup-items>
        <kendo-radiogroup-item html-attributes="@attributes" label="Yes" value="true"></kendo-radiogroup-item>
        <kendo-radiogroup-item label="No" value="false"></kendo-radiogroup-item>
    </kendo-radiogroup-items>
</kendo-radiogroup>

Here is a Telerik REPL that further showcases this approach:

• Telerik REPL for ASP.NET Core Example

"Be advised, that this action would be required due to the fact that the inner RadioButton items will be constructed on the client-side via a jQuery constructional logic. In comparison to the most outward container which will be rendered on the server. This is why directly injecting raw attributes cannot be applied to the inner items."

I hope this makes sense and keeps you posted with the status of the item :)

I wish you all the best!

Kind Regards,
Alexander
Progress Telerik