It can happen that the orders are out of sync for the refund status. Then it shows the order is refunded in Magento 2 admin area, but not in Adyen Customer Area.
There are several ways of issuing a refund:
- Regular refund
- Offline refund
An offline refund does not trigger the Adyen payments platform, and can not be intercepted by Adyen's plugin, which can cause this issue to arise. To prevent this from happening, make sure to follow the steps described in how to issue a refund with Adyen Magento 2 Plugin.