Broken 3 column layout

gistfile1.txt

/**
 * Internal dependencies
 */
import './style.scss';

/**
 * External dependencies
 */
import { __ } from '@wordpress/i18n';
import { registerBlockType } from '@wordpress/blocks';
import { InnerBlocks } from '@wordpress/editor';

const TEMPLATE = [
	[ 'core/heading', {
		className: 'wp-block-wccom-three-column-header',
		placeholder: __( 'Enter Title...', 'wccom' ),
	} ],
	[ 'core/columns', { className: 'wp-block-wccom-three-column-content' }, [
		[ 'core/column', {}, [
			[ 'core/heading', { placeholder: __( 'Enter Title...', 'wccom' ) } ],
			[ 'core/paragraph', { placeholder: __( 'Enter Description...', 'wccom' ) } ],
		] ],
		[ 'core/column', {}, [
			[ 'core/heading', { placeholder: __( 'Enter Title...', 'wccom' ) } ],
			[ 'core/paragraph', { placeholder: __( 'Enter Description...', 'wccom' ) } ],
		] ],
		[ 'core/column', {}, [
			[ 'core/heading', { placeholder: __( 'Enter Title...', 'wccom' ) } ],
			[ 'core/paragraph', { placeholder: __( 'Enter Description...', 'wccom' ) } ],
		] ],
	] ],
];

registerBlockType( 'wccom/three-column-content', {
	title: __( 'Three Column Content', 'wccom' ),
	icon: 'cart',
	category: 'wccom',
	keywords: [
		__( 'woo', 'wccom' ),
		__( 'header', 'wccom' ),
		__( 'columns', 'wccom' ),
	],

	edit() {
		return (
			<InnerBlocks template={ TEMPLATE } />
		);
	},

	save() {
		return (
			<InnerBlocks.Content />
		);
	},
} );