Why is my order status Settled or SentForSettle after I refunded it on Magento?
The status might not be yet synced
It’s possible the refund status is out of sync between the two environments. For example, it can show the order being refunded in Magento 2, but not in your Adyen Customer Area.
You can issue a refund in the regular manner but also offline. This issue appears when an offline refund doesn’t trigger the Adyen platform and can’t be intercepted by Adyen's plugin.
Tip: To prevent this, follow the steps described in how to issue a refund with Adyen Magento 2 Plugin.
Find more details on this topic.Go to Adyen Docs