Starting in 2019, PayPal added more complex fees to several kinds of payments that Ethnio issues automatically as part of our incentives feature. This means that we have to charge a surcharge for every recipient in a batch with PayPal rewards turned on, and that is based on their fees for U.S. and international payments. Unfortunately we cannot charge for only your recipients that choose PayPal due to limitations of the PayPal API.
Your recipients never pay or see any fees.
This is simply to cover the range of fees that PayPal charges via their API after an order is placed.