Two Different Shipping Rates

Our Woo Commerce Store currently runs with a Table Rate shipping based on the cost of the items within the basket. We want to also add set shipping rates for some of our new products, that only applies to those at a flat rate. We have set this up and it works fine. However, if you purchase one of the items that uses a flat rate shipping, and an item that uses the table rate shipping, you can select which shipping you would like to use, meaning the person can get shipping for ALOT cheaper than it would normally be as they are only paying for the shipping of the one flat rate item.

Is there a way to ensure that either only the higher shipping rate is displayed, or a way to add the two shipping rates together at the checkout?

Thanks for your help!

https://ww.wp.xz.cn/plugins/woocommerce/