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.
return;
    }
    if (Number.isInteger(width)) {
      if (width > 0) {
        const maxWidth = (rect[2] - rect[0]) / 2;
        const maxHeight = (rect[3] - rect[1]) / 2;
        
        
        
        if (
          maxWidth > 0 &&
          maxHeight > 0 &&
          (width > maxWidth || width > maxHeight)
        ) {
          warn(`AnnotationBorderStyle.setWidth - ignoring width: ${width}`);
          width = 1;
        }
      }
      this.width = width;
    }
  }
  /**
   * Set the style.
   *
   * @public
   * @memberof AnnotationBorderStyle
   * @param {Name} style - The annotation style.
   * @see {@link shared/util.js}
   */
  setStyle(style) {