Issue with custom function

[xxedgexx]

After updating to woo 3.5.4, I noticed in the dashboard, only one of my products in my catalog was returning:

https://snag.gy/iDEmgy.jpg

It turns out this function, which I copied from some other site, was causing problems. The purpose of the function is to display the discounted price when a coupon code is applied:

add_filter('woocommerce_get_price_html', 'woocommerce_get_price_html', 10, 2 );
function woocommerce_get_price_html( $price, $product ) {

if ( WC()->cart->has_discount() ) {

	$values = array (
		'data'		=> $product,
		'quantity'	=> 1
	);

	$coupons = WC()->cart->get_coupons();

	$_price = $product->get_price();
	$undiscounted_price = $_price;

	if ( ! empty( $coupons ) ) {

		foreach ( $coupons as $code => $coupon ) {

			if ( $coupon->is_valid() && ( $coupon->is_valid_for_product( $product, $values ) || $coupon->is_valid_for_cart() ) ) {
				$discount_amount = $coupon->get_discount_amount( 'yes' === get_option( 'woocommerce_calc_discounts_sequentially', 'no' ) ? $_price : $undiscounted_price, $values, true );
				$discount_amount = min( $_price, $discount_amount );
				$_price          = max( $_price - $discount_amount, 0 );
			}

			if ( 0 >= $_price ) {
				break;
			}
		}
		if ( ( $product->get_price() > 0 ) && ( $undiscounted_price !== $_price ) )
			$price = wc_format_sale_price( wc_get_price_to_display( $product, array( 'price' => $undiscounted_price ) ), $_price ) . $product->get_price_suffix();
	}

}

return $price;

}

Any obvious issue or changes that need to be made after the 3.5.4 update?