Corrupted Pricing

Just purchased Woocommerce booster.

Although at first the multi currency was working ok.
I used EUR + USD + BHC (bit coin cash)

But suddenly the rates changed in a strange way. The base currency (Euro, changed into a not rounded number)
an example :
https://authenticarts.eu/product/deborah-j-garrett-magnet-keizersgracht/

The base currency is euro and price for product is 4 euro (set in product price)

even when plugin is deactivated it still shows as 3.31 euro.

Now I really have a problem. How do I get my original pricing back? (to 4 euro)

Please help.

Kind Regards,

Ray Edgar

The page I need help with: [log in to see the link]