cart total and checkout page total are different. In checkout page VAT is applied before deduct discount form subtotal. that is the reason total is vary in cart page and checkout page. Please solve this issue.
VAT should be applied after deduct discount from subtotal in checkout page. Please check the snapshot links too
https://insuserve.com/Cart%e2%80%93eliquidglobal.png
https://insuserve.com/Checkout%E2%80%93eliquidglobal.png