Shipping costs not updating for multiple items

Hello Verityg,

Thank you for using my plugin.
Can you verify the difference prices on the official AU Post Calculator?
https://auspost.com.au/parcels-mail/calculate-postage-delivery-times/
Sometimes when you send a product within close areas, the prices won’t change even if you increased the quantity (weight and size).

Please verify the prices on the calculator and let me know if you still see a difference.

Best Wishes,
Waseem