Rate increases from product to cart to checkout

I have tried many settings to see what might be causing this, but i’m at a loss here and can not launch my website until this is fixed.

Example:

Base currency is EUR, product price is €139.99 (incl VAT @ 23%).
Exchange Rate is 1.118 + 0.05.
USD converted price is USD $163.51 (which shows on product page as normal).
When on CheckoutPage, the USD Price shows USD $223.06.

This is the same issue for any other currency that is not the base currency.