Hi ashleymhowe,
Setting up shipping in your PayPal profile does not work with Express Checkout. That only works with Payments Standard.
Express Checkout leaves it up to the website/application to calculate shipping, tax, handling, etc. and include it all in the API requests that are sent to PayPal servers.
This plugin will utilize the shipping calculator(s) that you have configured in the WooCommerce shipping settings. You'll need to setup shipping costs there instead of within your PayPal account.
Hope that helps. Let me know if you have troubles with that.