woocommerce plugin returns null results

We're building a brand new website on woocommerce with all the latest versions of everything, have installed your plugin, created and added the access token.

When testing an order with a 1kg 10x10x10cm product, shipping locally within Australia or to USA with valid addresses, it returns no shipping options.

This may be a clue to help diagnose the issue: I tried "Disable Easyship" but clicking on the button does nothing.