[MCCY] Incorrect shipping amount conversion in the Woo FedEx Extension

[bborman22]

Describe the bug

When adding a shippable product to the cart with the store currency set to USD, the shipping option FedEx Ground Home Delivery shows a cost of approximately $40. However, when the shopper switches the currency to JPY using the currency switcher, the same shipping option is displayed as 11,000 JPY. According to the WooPayments conversion rate (1 USD = 142 JPY), the correct converted amount should be approximately 5,680 JPY (~$40 USD), but the system is calculating it closer to 77 USD.

To Reproduce

Instructions to set up the extension: #3131

1. Set the store currency to USD.
2. Add a shippable product to the cart.
3. Observe the FedEx Ground Home Delivery shipping cost in USD.
4. Switch the store currency to JPY using the currency switcher.
5. Observe the FedEx Ground Home Delivery shipping cost in JPY.

Screenshots

Additional context

• Destination address used: San Francisco, CA, 94110
• Origin postcode: 34480

[bborman22]

Closed by #9985