Validation error: PayPal amounts do not match (gross xx.xx). Order status change

Here are the versions we are running:

WordPress: 4.5.3
WooCommerce: 2.6.2 – i just upgraded to this from 2.6.1
PHP Version: 5.4.43

The issue we are having is when an order is paid for via PayPal standard, we get a new order notification email. The email has the QTY and price of everything ordered and the shipping price. Everything looks great. But when the order charged to the customers PayPal account, they are NOT being charged shipping costs. Just the gross order amount.

The order is then put on hold within WooCommerce and we get an order note placed on the order such as:

Validation error: PayPal amounts do not match (gross 56.00). Order status changed from Pending Payment to On Hold.

This particular order was for $56 (products) and $17 for shipping. The order notification email from WooCommerce shows $56 and $17 for shipping. The email from PayPal shows just the $56 product charge.

We’ve gone back through our orders and seen this happen at least 3 times in the past month.

If an order is placed through our Stripe add-on it works just fine.

I turned on logging for payapl and included part of it here and removed some sensitive data

[body] => Array
        (
            [cmd] => _notify-validate
            [mc_gross] => 56.00
            [invoice] => WC-2174
            [protection_eligibility] => Ineligible
            [item_number1] => 1004
            [tax] => 0.00
            [item_number2] => 1002
            [payer_id] => 9DBPNXGZTP82Y
            [payment_date] => 08:30:06 Jul 08, 2016 PDT
            [payment_status] => Completed
            [charset] => windows-1252
            [mc_shipping] => 0.00
            [mc_handling] => 0.00
            [first_name] => Angela
            [mc_fee] => 2.48
            [notify_version] => 3.8
            [custom] => {"order_id":2174,"order_key":"wc_order_577fc6e8a2014"}
            [payer_status] => unverified
            [business] => [email protected] HIDDEN ON PURPOSE
            [num_cart_items] => 2
            [mc_handling1] => 0.00
            [mc_handling2] => 0.00
            [verify_sign] => AKT9YF3SRMaJwCYrIl0ZYYCB3ktdAcDexPRPiG5M44qcxn8E-UrcyUfd
            [payer_email] => [email protected] HIDDEN ON PURPOSE
            [mc_shipping1] => 17.00
            [mc_shipping2] => 0.00
            [txn_id] => 77W47246GW886902K
            [payment_type] => instant
            [last_name] => Doe
            [item_name1] => Pretty Pewter ( Color: Pretty Pewter,
Size: Small (7-8) )
            [receiver_email] => [email protected] HIDDEN ON PURPOSE
            [item_name2] => Hi-Ho Silver ( Color: Hi-Ho Silver,
Size: Small (7-8) )
            [payment_fee] => 2.48
            [quantity1] => 3
            [quantity2] => 1
            [receiver_id] => ZTUMSMN25VHWE
            [txn_type] => cart
            [mc_gross_1] => 59.00
            [mc_currency] => USD
            [mc_gross_2] => 14.00
            [residence_country] => CA
            [transaction_subject] => {"order_id":2174,"order_key":"wc_order_577fc6e8a2014"}
            [payment_gross] => 56.00
            [ipn_track_id] => ddac991d3fb48
        )

    [timeout] => 60
    [httpversion] => 1.1
    [compress] =>
    [decompress] =>
    [user-agent] => WooCommerce/2.6.1

I saw that there were people having similar issues about a year ago, but apparently that bug was patched long ago within WooCommerce.

This particular order was to a customer in Canada, but it has happened with both domestic and international customers.

https://www.ads-software.com/plugins/woocommerce/