Hello,

I did test this but I was not able to reproduce this behavior. Is it possible to provide/attach a small sample that illustrates the issue you are having?

Can Someone help me?

My XamDataGrid - XAML :

<my:XamDataGrid vm:ControlBehaviours.DoubleClickCommand="{Binding CommandEditUserGroups}"
                                            IsSynchronizedWithCurrentItem="True"
                                            Margin="0,46,0,0" Name="DataGrid" Theme="Generic" AllowDrop="False" 
                                            GroupByAreaLocation="AboveDataArea" DataSource="{Binding UserGroupsCollectionView,Mode=TwoWay}"
                                            GroupByAreaMode="MultipleFieldLayoutsFull"  Background="White" Foreground="White" ActiveRecord="{Binding Path=ItemCurrent,Mode=TwoWay}">
                               
                                <my:XamDataGrid.FieldLayouts>
                                <my:FieldLayout Description="UserGroups" >
                                        <my:Field Name="BranchID" Visibility="Collapsed">
                                            <my:Field.Settings>
                                                <my:FieldSettings AllowHiding="Never"/>
                                            </my:Field.Settings>
                                        </my:Field>
                                            <my:Field Name="ID" Label="Código" />
                                    <my:Field Name="Name" Label="Nome" />
                                        <my:Field Name="Remarks" Visibility="Collapsed">
                                            <my:Field.Settings>
                                                <my:FieldSettings AllowHiding="Never"/>
                                            </my:Field.Settings>
                                        </my:Field>
                                            <my:Field Name="Error" Visibility="Collapsed">
                                            <my:Field.Settings>
                                                <my:FieldSettings AllowHiding="Never"/>
                                            </my:Field.Settings>
                                        </my:Field>
                                        <my:Field Name="CreatedByUser" Visibility="Collapsed">
                                            <my:Field.Settings>
                                                <my:FieldSettings AllowHiding="Never"/>
                                            </my:Field.Settings>
                                        </my:Field>
                                        <my:Field Name="CreatedDate" Visibility="Collapsed">
                                            <my:Field.Settings>
                                                <my:FieldSettings AllowHiding="Never"/>
                                            </my:Field.Settings>
                                        </my:Field>
                                        <my:Field Name="UserLastChange" Visibility="Collapsed">
                                            <my:Field.Settings>
                                                <my:FieldSettings AllowHiding="Never"/>
                                            </my:Field.Settings>
                                        </my:Field>
                                        <my:Field Name="DateLastChange" Visibility="Collapsed">
                                            <my:Field.Settings>
                                                <my:FieldSettings AllowHiding="Never"/>
                                            </my:Field.Settings>
                                        </my:Field>
                                    </my:FieldLayout>
                                </my:XamDataGrid.FieldLayouts>
                               
                                <my:XamDataGrid.FieldSettings>
                                    <my:FieldSettings  AllowRecordFiltering="True" AllowSummaries="True" AllowEdit="False"
                                                       SummaryUIType="MultiSelect" FilterOperandUIType="Default"
                                                       FilterClearButtonVisibility="Visible" AutoSizeOptions="All"
                                                       CellClickAction="SelectRecord" DataValueChangedScope="Default"  />
                                </my:XamDataGrid.FieldSettings>
                                <my:XamDataGrid.FieldLayoutSettings>
                                    <my:FieldLayoutSettings ExpansionIndicatorDisplayMode="Never" AllowFieldMoving="WithinLogicalRow" AllowAddNew="False" AllowDelete="False"
                                                            SelectionTypeRecord="Single" AutoGenerateFields="True" MaxSelectedRecords="1"
                                                            HighlightAlternateRecords="True" HeaderPrefixAreaDisplayMode="FieldChooserButton"
                                                            HeaderPlacement="OnTopOnly" HeaderPlacementInGroupBy="OnTopOnly">
                                    </my:FieldLayoutSettings>
                                </my:XamDataGrid.FieldLayoutSettings>
                                <my:XamDataGrid.GroupByAreaMulti>
                                    <my:GroupByAreaMulti Foreground="Black" Prompt1="" Prompt2="Clique e Arraste uma coluna para agrupar."
                                                         IsExpanded="True"/>
                                </my:XamDataGrid.GroupByAreaMulti>
                            </my:XamDataGrid>

CodeBehind ExcelExporter :

   public static void ExportExcel(XamDataGrid DataGrid)
        {                                                      
            string FileNameComplete = System.IO.Path.GetTempFileName() + ".xls"; ;                      
            DataPresenterExcelExporter ExcelExporte = new DataPresenterExcelExporter();
            ExportOptions Options = new ExportOptions();           
           FormatSettings Format = new FormatSettings() { FillPattern = FillPatternStyle.Solid, FillPatternBackgroundColor = Colors.Black, FillPatternForegroundColor = Colors.LightBlue };
            DataPresenterExcelExporter.SetExcelLabelFormatSettings(DataGrid.FieldSettings, Format);           
            ExcelExporte.Export(DataGrid, FileNameComplete, WorkbookFormat.Excel97To2003, Options);
            System.Diagnostics.Process OpenExcel = new System.Diagnostics.Process();
            OpenExcel.StartInfo.FileName = FileNameComplete;
            OpenExcel.Start();          
        }

Thanks