Flexcel.vcl: Shapes disappear when rows are programmatically collapsed

We create excel files in which cell values are represented by shapes. The shapes are positioned in the cell.

The code seems to be taken from APIMate:

                ShapeOptions1            := TShapeProperties_Create;
                ShapeOptions1.Anchor     := TClientAnchor.Create(TFlxAnchorType.MoveAndResize, lZeile, lBalken, i + S.KW1, 0, lZeile, 251, i + S.KW1 +1, 0);
                ShapeOptions1.ShapeType  := TShapeType.Rectangle;
                ShapeOptions1.ObjectType := TObjectType.MicrosoftOfficeDrawing;
                ShapeOptions1.ShapeName  := 'Abverkauf';
                ShapeOptions1.RotateTextWithShape := true;
                ShapeOptions1.ShapeThemeFont := TShapeFont_Create(TFontScheme.Minor, TDrawingColor.FromTheme(TThemeColor.Background1));
                ShapeOptions1.Print := true;
                ShapeOptions1.Visible := true;
                ShapeOptions1.ShapeGeometry := '<?xml version="1.0" encoding="utf-8" standalone="yes"?><a:shapeGeom xmlns:a="http://schemas.openxmlformats.org/drawingml/2006/main"><a:prstGeom'
                  + ' prst="rect"><a:avLst /></a:prstGeom></a:shapeGeom>';
                ShapeOptions1.ShapeOptions.SetValue(TShapeOption.fillColor, 255);
                ShapeOptions1.ShapeOptions.SetValue(TShapeOption.fillOpacity, 0.5);
                ShapeOptions1.ShapeOptions.SetValue(TShapeOption.fillBackColor, 134217808);
                ShapeOptions1.ShapeOptions.SetValue(TShapeOption.fFilled, true);
                ShapeOptions1.ShapeOptions.SetValue(TShapeOption.lineColor, 5296274);
                ShapeOptions1.ShapeOptions.SetValue(TShapeOption.lineWidth, 12700);
                ShapeOptions1.ShapeOptions.SetValue(TShapeOption.shadowColor, 0);
                ShapeOptions1.ShapeOptions.SetValue(TShapeOption.wzName, 'Abverkauf');

Outline levels are added:

 XLSX.SetRowOutlineLevel(lErsteTeile - 1, lLetzteZeile + 1, 1);

When we collapse the document by

XLSX.CollapseOutlineRows(1, TCollapseChildrenMode.Collapsed);

the shapes in the collapsed rows are not visible anymore when the rows ar uncollapsed.

When we collapse the document by Excel OLE

        Excel := CreateOleObject('Excel.Application');
        Excel.DisplayAlerts := False; 

the shapes stay in the cells.

I took a look in the created Excel files and found a difference:

On the left side is the drawing1.xml from the file collapsed by flexcel.
It looks like anchor values get lost.

There indeed seems to be an error when we hide the row, in that the size is set to 0 (because it should be hidden with the row hidden), but we don't restore when unhiding the row.

We are investigating it, I'll let you know when we find out what is happening.