Problem with smart panel

Hi, Good night. 

I have a simple smart panel with a grid with checkbox. 

If in my datasource i use “AggregateTo” the checkbox (for some reason) turned into readOnly (and i cant select the values) and when y delete “AggregateTo” the checkbox works fine. Can you help me please?

I need to group by the result.

my query/datasource

        public SelectFrom<Contact>
            .InnerJoin<CEBidPackageManagementPhaseCodeDetail>
            .On<CEBidPackageManagementPhaseCodeDetail.contactId.IsEqual<Contact.contactID>>
            .InnerJoin<CEBidPackageManagementPhaseCode>
            .On<CEBidPackageManagementPhaseCodeDetail.idBidPackageManagementPhaseCode.IsEqual<CEBidPackageManagementPhaseCode.id>>
            .Where<CEBidPackageManagementPhaseCodeDetail.bidPackageNbr.IsNotEqual<CEBidPackage.estimateNbr.FromCurrent>.And<CEBidPackageManagementPhaseCode.idPhaseCode.IsEqual<CEBidPackageManagementPhaseCode.idPhaseCode.FromCurrent>>>
            .AggregateTo<GroupBy<Contact.contactID>, GroupBy<Contact.fullName>, GroupBy<Contact.displayName>>
            .OrderBy<Contact.fullName.Asc>
            .View SPPreviouslyInvited;

Aspx Smart panel.

    <px:PXSmartPanel ID="PXSmartPanel11" runat="server" Key="SPPreviouslyInvited" LoadOnDemand="true" Width="700px" Height="800px"
        Caption="Add Previously Invited" CaptionVisible="true" AutoRepaint="true" DesignView="Content" ShowAfterLoad="true">

        <px:PXGrid ID="PXGrid22" runat="server" DataSourceID="ds" Style="height: 189px;"
            AutoAdjustColumns="true" Width="100%" SkinID="Details" AdjustPageSize="Auto" AllowSearch="True"
            FastFilterFields="FullName,DisplayName" BatchUpdate="true">
            <CallbackCommands>
                <Refresh CommitChanges="true"></Refresh>
            </CallbackCommands>
            <ClientEvents AfterCellUpdate="UpdateItemSiteCell" />
            <ActionBar PagerVisible="False">
                <PagerSettings Mode="NextPrevFirstLast" />
            </ActionBar>
            <Levels>
                <px:PXGridLevel DataMember="SPPreviouslyInvited">
                    <Mode AllowAddNew="false" AllowDelete="false" />
                    <RowTemplate>
                    </RowTemplate>
                    <Columns>
                        <px:PXGridColumn DataField="Selected" TextAlign="Center" Type="CheckBox" AutoCallBack="True" Width="40px" AllowCheckAll="True" />
                        <px:PXGridColumn DataField="FullName" Width="300px" />
                        <px:PXGridColumn DataField="DisplayName" Width="300px" />
                    </Columns>
                    <Mode AllowAddNew="false" AllowUpdate="false" AllowDelete="false" />
                </px:PXGridLevel>
            </Levels>
                        <ActionBar>
                <Actions>
                    <FilterBar Enabled="True"></FilterBar>
                    <FilterBar GroupIndex="3"></FilterBar>
                    <FilterBar Order="0"></FilterBar>
                    <FilterBar ToolBarVisible="Top"></FilterBar>
                    <AddNew Enabled="False" />
                    <Upload Enabled="True"></Upload>
                </Actions>
            </ActionBar>
            <AutoSize Enabled="true" />
        </px:PXGrid>
        <px:PXPanel ID="PXPanel11" runat="server" SkinID="Buttons">

            <px:PXButton ID="PXButton11" runat="server" Text="Add & Close" DialogResult="OK" />
            <px:PXButton ID="PXButton22" runat="server" DialogResult="Cancel" Text="Cancel" />
        </px:PXPanel>
    </px:PXSmartPanel>

 Example without AggregateTo in my datasource (the checkbox works fine!)

Example with AggregateTo in my datasource (the checkbox is readonly)

I need to use the groupBy/AggregateTo in my datasource and the checkbox in my smartPanel works fine, please help. Thanks