Fix shipping cost issue in Google Merchant Centre

Assistance to resolve the following issue in a Google Merchant Centre Feed.

Weight based shipping is enable on the site (woocommerce)
Weight based shipping matches the Merchant Center delivery services settings.
Weight of product is enabled in the feed.
Feed is generated on the site using a plugin linked to the merchant centre.

Issue:
Your Merchant Center account presently does not meet the following Shopping ads product data specification requirements:
Inaccurate delivery costs (due to inconsistent delivery costs between your feed and the checkout pages on your website)
The delivery costs in your product data don't match the delivery costs on the checkout pages on your website.

Examples of violations:
Value on the landing page - 24.99GBP
Value in the data feed - 9.99GBP
Postcode - SW1W 9TQ