I paid a deposit for renting an apartment in Barcelona. The owner accepted payment thru PayPal (a big plus versus most other owners want you to REMIT money to their bank accounts). When I paid on PayPal, the page told me it would access 2% forex fee, to become part of the payment.

When the charge hit my AMEX, the forex fee was included in the line item.

So may be your previous payments had forex fee, but were not billed separately, versus now it was billed separately. Just a guess.