fontFamily renders on ckeditor5 but not fontSize

import BlockQuote from '@ckeditor/ckeditor5-block-quote/src/blockquote.js';
import ClassicEditor from '@ckeditor/ckeditor5-editor-classic/src/classiceditor.js';
import Essentials from '@ckeditor/ckeditor5-essentials/src/essentials.js';
import Font from '@ckeditor/ckeditor5-font/src/font';
import Heading from '@ckeditor/ckeditor5-heading/src/heading.js';
import IndentBlock from '@ckeditor/ckeditor5-indent/src/indentblock.js';
import List from '@ckeditor/ckeditor5-list/src/documentlist.js';
import ListProperties from '@ckeditor/ckeditor5-list/src/documentlistproperties.js';
import Paragraph from '@ckeditor/ckeditor5-paragraph/src/paragraph.js';
import Table from '@ckeditor/ckeditor5-table/src/table.js';
import TableToolbar from '@ckeditor/ckeditor5-table/src/tabletoolbar.js';

class Editor extends ClassicEditor {}

Editor.builtinPlugins = [
  Essentials,
  Heading,
  IndentBlock,
  List,
  ListProperties,
  Paragraph,
  Table,
  TableToolbar,
  Font,
];

Editor.defaultConfig = {
  toolbar: {
    items: [
      'bulletedList',
      'numberedList',
      '|',
      'outdent',
      '|',
      'insertTable',
      'fontFamily',
      'fontSize',
    ],
  },
  language: 'en',
  table: {
    contentToolbar: ['tableColumn', 'tableRow', 'mergeTableCells'],
  },
  licenseKey: '',
};

export default Editor;