Thanks Emzo,
I’d actually already reached this point myself but appreciate your help 
I guess it’s good to note for anyone hoping to get WooCommerce working glitch free with FastCGI Caching
skip_cache_uri: /wp-admin/|/xmlrpc.php|wp-.*.php|/feed/|index.php|sitemap(_index)?.xml|* "/store.*|/cart.*|/my-account.*|/checkout.*|/addons.*
skip_cache_cookie: comment_author|wordpress_[a-f0-9]+|wp-postpass|wordpress_no_cache|wordpress_logged_in|woocommerce_cart_hash|woocommerce_items_in_cart|wp_woocommerce_session_