Boundary of FreeText Annotation disappears on saving

Product: WebViewer

Product Version: 8.11

I’ve added a freetext annotation that comes with a rectangular boundary in the same colour as the text. Once the annotation is saved and the document is opened once again, the text is still showing, but the boundary has disappeared.

Here is some of the code:

const freeText = new Annotations.FreeTextAnnotation();
              // @todo Lock write mode
              freeText.ToolName = "Gruppe Poststempel vereinfacht";
              freeText.Id = "stamp-" + uuidv4();
              freeText.PageNumber = pos.pageNumber;
              freeText.Rotation = pos.rotation;
              freeText.X = pos.x;
              freeText.Y = pos.y;
              freeText.Width = pos.width;
              freeText.Height = pos.height;
              freeText.Opacity = pos.margin;

              //freeText.TextVerticalAlign = "center";
              freeText.FontSize = '11pt';
              freeText.TextAlign = 'center';
              freeText.TextVerticalAlign = 'center';
              freeText.TextColor = new Annotations.Color('#FF0000');
              freeText.StrokeThickness = 0.5;
              freeText.Color = new Annotations.Color('#FF0000');
              freeText.Locked = false;

              let content = "";
             content = `Text in line 1\n` +
                    `text in line 2 including a date ${date}\n`+
                    `text in line 4\n`+
                    `text in line 5\n`+


              annotationManager.addAnnotation(freeText, { autoFocus: false });

Steps to reproduce:

  1. Switch into edit-mode
  2. Add stamp to document
  3. Save document through default save-function
  4. Switch view to another document
  5. Return to original document and see that the boundary has disappeared
    (The boundary appears once I click on the annotation, but disappears again as soon as I click anywhere else)

Here is a short video showing the steps listed above and the effect:

Is there anything I can do to save the boundary as well as the text?