In file https://github.com/mozilla/pdf.js/files/5249872/product1.pdf, the fifth text widget has a default appearance using font F1 and this one is neither in DR nor in AcroForm but in AP::N::Resources.
this.data.modificationDate = this.modificationDate;
      }
      this.data.hasPopup = parent.has("Popup");
      if (!parent.has("C")) {
        
        this.data.color = null;
      } else {
        this.setColor(parent.getArray("C"));
        this.data.color = this.color;
      }
    } else {
      this.data.title = stringToPDFString(dict.get("T") || "");
      this.setCreationDate(dict.get("CreationDate"));
      this.data.creationDate = this.creationDate;
      this.data.hasPopup = dict.has("Popup");
      if (!dict.has("C")) {
        
        this.data.color = null;
      }
    }
  }
  /**
   * Set the creation date.
   *
   * @public
   * @memberof MarkupAnnotation
   * @param {string} creationDate - PDF date string that indicates when the
   *                                annotation was originally created
   */
  setCreationDate(creationDate) {