gantt
                                
                                 gantt copied to clipboard
                                
                                    gantt copied to clipboard
                            
                            
                            
                        There are duplicate element nodes

@Hsensor, Thank you for letting us know about that issue. I added it as a bug to our internal bug tracker. The dev team will fix it in the future, but I cannot give you any ETA.
As a workaround, you can initialize Gantt twice: https://snippet.dhtmlx.com/h02ycyxd