It can happen that the orders are out of sync for the refund status. 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.
Make sure to follow the documentation on how to issue a refund with Adyen Magento 2 Plugin.