Order purchased from amasty reward point using afterpay payment method have 1.82 dollars on every order deduction when refunded with credit memo

A very strange issue, when a magento Order paid with the amasty reward point( https://amasty.com/reward-points-for-magento-2.html ) using Afterpay payment method have 1.82 dollars deduction on every order, when refunded with credit memo.