Storefront won't stop displaying local currencies.

Hi there.

We are currently using a third-party app to hide some of the prices for our custom products. However, non-custom products still have their prices displayed for all customers. To maintain consistency, we would like to receive payment only in US dollars. Our store settings are set to USD for currency, and we’ve turned off the “Convert to Local Currency” option under Markets.

However, when I access our storefront from my location in Japan, the open prices are still shown in Japanese yen. How can we fix this?