Free shipping + ECB exchange module

[beetea2]

I offer free shipping for orders over US$60.

Shipping -> Carriers -> Free Shipping -> Billing by price -> Minimum order value = US$60 

No matter what currency I select, if the amount is more than 60 of that currency the customer gets free shipping.

e.g. Cart has CA$66.79 (equal to US$48.00) = Free shipping.

Am I doing something wrong?

TB 1.6.0

 PHP version 8.3.24 

Panda theme

ECB Exchange Rate Module 1.1.0