German Market wrong Tax Calculations

add_action( 'after_setup_theme', function() {
	
	remove_filter( 'woocommerce_cart_totals_fee_html', array( 'WGM_Fee', 'show_gateway_fees_tax' ), 10, 2 );
	remove_filter( 'woocommerce_cart_totals_get_fees_from_cart_taxes', array( 'WGM_Fee', 'cart_totals_get_fees_from_cart_taxes' ), 10, 3 );	
	remove_filter( 'woocommerce_get_order_item_totals', array( 'WGM_Fee', 'add_tax_string_to_fee_order_item' ), 10, 2 );
	remove_filter( 'woocommerce_order_get_tax_totals', array( 'WGM_Fee', 'add_fee_to_order_tax_totals' ), 10, 2 );
	
	add_filter( 'woocommerce_cart_totals_fee_html', function( $fee_html, $fee ) {
		
		if ( class_exists( 'WGM_Tax' ) ) {
			$tax_display 		= get_option( 'woocommerce_tax_display_cart' );

			if ( isset( $fee->tax_data ) && is_array( $fee->tax_data ) ) {
				foreach ( $fee->tax_data as $rate_id => $amount ) {
					$tax_label 	= WC_Tax::get_rate_label( $rate_id );
					$rate_percent = floatval( WC_Tax::get_rate_percent( $rate_id ) );
					$tax_string = WGM_Tax::get_excl_incl_tax_string( $tax_label, $tax_display, $rate_percent, wc_price( $fee->tax ) );
					$fee_html .= sprintf( '
 %s ', $tax_string );
					break;
				}
			}
		}		
		
		return $fee_html;
	}, 10, 2 );
	
	add_filter( 'woocommerce_get_order_item_totals', function( $items, $order ) {
		
		if ( is_a( $order, 'WC_Order_Refund' ) ) {
			$parent_id = $order->get_parent_id();
			$order = wc_get_order( $parent_id );
		}
		
		$tax_display = get_option( 'woocommerce_tax_display_cart' );
		
		foreach ( $order->get_fees() as $key => $fee ) {

			$search_key = 'fee_' . $key;

			if ( ! array_key_exists( $search_key, $items ) ) {
				continue;
			}
			
			$rate = array();
			$taxes = $fee->get_taxes();
			
			if ( isset( $taxes[ 'total' ] ) ) {

				foreach ( $taxes[ 'total' ] as $tax_rate_key => $tax_infos ) {

					$label = apply_filters( 'wgm_translate_tax_label', WC_Tax::get_rate_label( $tax_rate_key ) );
					$sum   = $fee->get_total_tax();
					$rate  = floatval( WC_Tax::get_rate_percent( $tax_rate_key ) );
					$tax_string = WGM_Tax::get_excl_incl_tax_string( $label, $tax_display, $rate, wc_price( $sum ) );
					$fee_html .= sprintf( '
 %s ', $tax_string );
					$items[ $search_key ][ 'value' ] .= $fee_html;
					
					break;
				}
			}
		}

		return $items;
		
	}, 10, 2 );
});