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 {
      id: this.data.id,
      value: this.data.fieldValue,
      defaultValue: this.data.defaultFieldValue,
      multiline: this.data.multiLine,
      password: this.hasFieldFlag(AnnotationFieldFlag.PASSWORD),
      charLimit: this.data.maxLen,
      comb: this.data.comb,
      editable: !this.data.readOnly,
      hidden: this.data.hidden,
      name: this.data.fieldName,
      rect: this.data.rect,
      actions: this.data.actions,
      type: "text",
    };
  }
}
class ButtonWidgetAnnotation extends WidgetAnnotation {