ATM charge?

I’ve tried BNL (BNP) atms in France, they don’t charge anything extra.

Are you sure you didn’t let the ATM do the conversion? You need to either “Decline” it, or choose a “Standard” withdrawal… the wording depends on ATMs.
Take a look at this message, there is a picture from a BNP (=BNL) atm: 5% ATM Fees in the First withdrawing within my country !