Zend certified PHP/Magento developer

Magento 2 WebShopApps Matrixrates – Use Grand Total rather than Subtotal

We’re currently using the WebShopApps Matrixrates extension on our Magento 2 installation.

The columns in our matrix rates file include:

‘Order Subtotal >’ and ‘Order Subtotal <=’

We have the following configuration:

Greater than ‘0’ and less than or equal to ‘349.99’ is a Shipping Price of ’45’

Greater than ‘350’ and less than or equal to ‘9999’ is a Shipping Price of ‘0’ (free shipping)

If a customer spends $350 but then applies a 10% discount code the overall spend is $315.

However, the Subtotal appears to remain at $350 with the Grand Total now being $315.

This results in the customer still receiving free shipping even though their overall spend is $315.

Is there any extension where the columns in the matrix rates can be set to Grand Total?

Or is there any other solution to this issue?

I hope I’ve explained the issue clearly enough.