Conflict between Tablepress extension and WP Custom Login plugin

Hi Again!

I have now little problem – Tablepress Single Cell Content Shortcode extension shortcodes have conflict with WP Custom Login plugin code.

Here ise WP custom Login plugin script:

<?php
/*
Plugin Name: WP Custom Login
Description: This plugin is adding the header and footer to the login page
Author: Ninos Ego
Version: 1.4.8
Author URI: https://ninosego.de/
*/

if( !isset($_REQUEST['interim-login']) )
{
	if( file_exists( get_theme_root() . '/' . get_stylesheet() . '/wp-custom-login.css' ) )
		wp_register_style( 'wp-custom-login', get_stylesheet_directory_uri() . '/wp-custom-login.css' );

	add_action( 'login_head', 'wp_custom_login_head_javascript' );
	function wp_custom_login_head_javascript() {
?>
		<script type="text/javascript">
			wp_custom_login_remove_element('wp-admin-css');
			wp_custom_login_remove_element('colors-fresh-css');

			function wp_custom_login_remove_element(id) {
				var element = document.getElementById(id);
				if( typeof element !== 'undefined' && element.value == '' )
					element.parentNode.removeChild(element);
			}
		</script>
<?php
	}

	add_action( 'login_head', 'wp_custom_login_header' );
	function wp_custom_login_header() {
		wp_enqueue_style( 'wp-custom-login' );

		do_action('wp_custom_login_header_before');
		get_header();
		do_action('wp_custom_login_header_after');
	}

	add_action( 'login_footer', 'wp_custom_login_footer' );
	function wp_custom_login_footer() {
		do_action('wp_custom_login_footer_before');
		get_footer();
		do_action('wp_custom_login_footer_after');
	}

	function wp_custom_login_is_login_page() {
		return in_array($GLOBALS['pagenow'], array('wp-login.php', 'wp-register.php'));
	}
}

I have via widget Single Cell Content Shortcodes in page header and with WP Custom Login script enabled I will see only page header until widget with shortcodes in login page.
Do You have any idea what exactly causing this conflict?

Tablepress Single Cell Content Shortcode extension works very well. WP Custom Login without Single Cell Content Shortcode shortcodes in header or footer also works very well.

PS. When I remove Single Cell Content Shortcode shortcodes from header, then login page content will be hidden since the next shortcode (etc in footer).

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