Everything set as Euro's but since installation everything is in dollars

The shop is configured in euro, FOX is installed, and the front end shows dollars. Nothing is broken — one setting is doing exactly what it was told.

The welcome currency

FOX has a welcome currency: the currency a first-time visitor sees before they have chosen anything. It exists so a shop based in one country can greet international traffic in a currency those visitors read more easily.

Out of the box it can point at a currency that is not your base one. If your WooCommerce base currency is EUR and the front end opens in USD, that is the setting to check first — plugin settings, then the welcome currency field. Set it to your base currency, or clear it, and new visitors will land on euro prices.

Two other candidates

Geo IP rules. If geolocation is enabled and a rule maps your own country — or the country your test traffic appears to come from — to USD, that rule wins over the base currency on the first request. Check the Geo IP tab.

A currency stored from an earlier visit. Your own browser may be holding a currency you selected while testing. It survives a page reload by design. Open the site in a private window to see what a genuinely new visitor gets.

Testing it properly

Always check in a private window or after clearing site data. A cached page adds a fourth variable, and chasing a currency bug through a warm cache wastes an afternoon.

Reference: the original report is on wordpress.org support.