WPML multicurrency problem

Hello,

I have a problem with getting the cart subtotal.
After I swithed currency in my page, I am stll getting old subtotal of the cart.

for example:
I have USD as default, the cart subtotal is 100
Then I switched to EUR and the function WC()->cart->subtotal in /includes/CriteriaAmmounts.php is returning 100 (it is subtotal for USD not for EUR)
Then I switched back to USD and the function WC()->cart->subtotal in /includes/CriteriaAmmounts.php is returning 80 (it is subtotal for EUR not for USD)

how can I fix it?

Thanks