Default currency not set properly

Working correctly on pages and cart.

On checkout, the value is in dollars, which means that the value is converted back to the default currency.
But, the currency name is still the same as for local – RSD instead of USD.

I am getting PayPal error (10605), because I only want to charge in USD.

I would like to have both currencies displayed on the checkout page, but only the local currency on other pages.