DropDownTree is not getting model values when it is bound with DataSource

[zdravkov]

Bug report

Reproduction of the problem

When we use DropDownTreeFor and bind the DropDownTree with DataSource the values are not applied

project available in ticket: 1458580

Environment

• **Kendo UI version:**2020.1.219

[IvanDanchev]

In addition to the DataSource remote binding scenario, the model is not properly updated when server binding is used:

@(Html.Kendo().DropDownTreeFor(m => m.ListOfRoles)
    .Checkboxes(c => c.Name("checkedItems"))
    .CheckAll(false)
    .AutoClose(false)
    .BindTo((IEnumerable<ServerCheckboxes.Models.ItemViewModel>)ViewBag.dropdowntreeData, (NavigationBindingFactory<DropDownTreeItem> mappings) =>
    {
        mappings.For<ServerCheckboxes.Models.ItemViewModel>(binding => binding.ItemDataBound((item, category) =>
        {
            item.Text = category.Role;
            item.Value = category.RoleID;
        })
        );
    })
    .Events(e => e.DataBound("onDataBound"))
)

A sample project can be found in Ticket ID: 1465800

[IvanDanchev]

Update (Ticket ID: 1465800): using a primitive value in the DDT:

.ValuePrimitive(true)

resolves the issue related to updating the model. So the behavior should be investigated in regards to not using primitive value.

[mihaela-lukanova]

Reported in 1564121

[yanisslav]

Reported in 1564199