Unable to fetch the selected filtered records in kendo

Below is my function which will add the selected values into the list

This function is working fine when I directly open the dropdown and select 'n' number of records. However, if I filter it by searching in the dropdown list of values and then I select a value, the previous selection is getting unchecked.

How can I make this function work for both cases where it is either filtered selection check or direct check?

Kendo DropDown Binding-

@(Html.Kendo().DropDownList()

.Name("ddlCompletedKD").AutoBind(false)

.HtmlAttributes(new { style = "width: 228px!important;", id = "ddlCompletedKD" })

.Template(")

.Events(e => e.Select("onSelect"))

.DataTextField("TypeName")

.DataValueField("TypeId")

.Filter("contains")

.DataSource(source =>

{

source.Read(read => { read.Action("LoadDDL", "Home").Data("LoadTypeParams");

}).ServerFiltering(false);

})

.Events(e => e

.DataBound("ddlDataBound"))

)

What i tried-

I had applied filter("contains") but search works if i select second record my previous record gets unselected