Refund Error

Hi,

I try to do a refund but always get the same error:
An error occurred while attempting to create the refund using the payment gateway API.

The Log:

2022-04-13T12:13:02+00:00 DEBUG  https://api.paypal.com/v2/checkout/orders/4YL653350H029545M
Response Debug ID: b181745c0d11
Response: Array
(
    [code] => 200
    [message] => OK
)

2022-04-13T12:13:02+00:00 DEBUG Trying to refund/void order 4YL653350H029545M, payments: {"authorizations":[],"captures":[{"id":"1KL44333B2994550D","status":"COMPLETED","amount":{"currency_code":"EUR","value":"460.00"},"final_capture":true,"seller_protection":{"status":"ELIGIBLE"},"invoice_id":"efebac-7705","custom_id":"7705","seller_receivable_breakdown":{"gross_amount":{"currency_code":"EUR","value":"460.00"},"paypal_fee":{"currency_code":"EUR","value":"11.80"},"net_amount":{"currency_code":"EUR","value":"448.20"}}}]}.
2022-04-13T12:13:04+00:00 DEBUG POST https://api.paypal.com/v2/payments/captures/1KL44333B2994550D/refund
Request Body: {"invoice_id":"efebac-7705","amount":{"currency_code":"EUR","value":"460.00"}}
Response Debug ID: 8ffcb728f51e1
Response: Array
(
    [code] => 422
    [message] => Unprocessable Entity
)

Response Body: {"name":"UNPROCESSABLE_ENTITY","message":"The requested action could not be performed, semantically incorrect, or failed business validation.","debug_id":"8ffcb728f51e1","details":[{"issue":"REFUND_FAILED_INSUFFICIENT_FUNDS","description":"Capture could not be refunded due to insufficient funds. Please check to see if you have sufficient funds in your PayPal account or if the bank account linked to your PayPal account is verified and has sufficient funds."}],"links":[{"href":"https://developer.paypal.com/docs/api/payments/v2/#error-REFUND_FAILED_INSUFFICIENT_FUNDS","rel":"information_link"}]}

2022-04-13T12:13:04+00:00 ERROR Refund failed: [UNPROCESSABLE_ENTITY] The requested action could not be performed, semantically incorrect, or failed business validation. https://developer.paypal.com/docs/api/payments/v2/#error-REFUND_FAILED_INSUFFICIENT_FUNDS

Thanks for any Help in advance.

Adrian