Problem with GridCheckBoxColumn Filter

[Support]

Hi, I have a problem with the GridCheckBoxColumn column filters.

This is my code.

<telerik:RadScriptManager ID="RadScriptManager1" runat="server" />
<telerik:RadStyleSheetManager ID="RadStyleSheetManager1" runat="server" />
<telerik:RadGrid ID="RadGrid1" runat="server"
    CellSpacing="0" Culture="it-IT" GridLines="None" DataKeyNames="ID"
    DataSourceID="SqlDataSource1" AutoGenerateColumns="false" Width="100%" AllowSorting="true" AllowPaging="true"
    AllowFilteringByColumn="true" GroupingSettings-CaseSensitive="false" EnableLinqExpressions="false" Skin="Bootstrap" >
    <MasterTableView DataKeyNames="ID" DataSourceID="SqlDataSource1" >
        <Columns>
            <telerik:GridBoundColumn SortExpression="Nome" HeaderText="Nome" DataField="Nome" ShowFilterIcon="false" AutoPostBackOnFilter="true" CurrentFilterFunction="Contains">
            </telerik:GridBoundColumn>
            <telerik:GridCheckBoxColumn SortExpression="Test 1" HeaderText="Test 1" DataField="Test 1" ShowFilterIcon="false" AutoPostBackOnFilter="true" CurrentFilterFunction="EqualTo">
            </telerik:GridCheckBoxColumn>
            <telerik:GridCheckBoxColumn SortExpression="Test 2" HeaderText="Test 2" DataField="Test 2" ShowFilterIcon="false" AutoPostBackOnFilter="true" CurrentFilterFunction="EqualTo">
            </telerik:GridCheckBoxColumn>
            <telerik:GridCheckBoxColumn SortExpression="Test 3" HeaderText="Test 3" DataField="Test 3" ShowFilterIcon="false" AutoPostBackOnFilter="true" CurrentFilterFunction="EqualTo">
            </telerik:GridCheckBoxColumn>
            <telerik:GridCheckBoxColumn SortExpression="Test 4" HeaderText="Test 4" DataField="Test 4" ShowFilterIcon="false" AutoPostBackOnFilter="true" CurrentFilterFunction="EqualTo">
            </telerik:GridCheckBoxColumn>
        </Columns>
        <SortExpressions>
            <telerik:GridSortExpression FieldName="Nome" SortOrder="Ascending" />
        </SortExpressions>
    </MasterTableView>
</telerik:RadGrid>
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ProviderName="System.Data.SqlClient" ConnectionString="<%$ ConnectionStrings:StrConnection %>" SelectCommand="SELECT Nome, [Test 1], [Test 2], [Test 3], [Test 4], [ID] FROM vista_r WHERE [ID R] = 1" >
</asp:SqlDataSource>

 

Filters only start working after I click on the 4 GridCheckBoxColumn filters.


Here a sample video

How can I solve?

Thank you.