Delivery error when replying to an email with "Hide My Email" address

I received an Email that was sent to a "Hide My Email" address which I created.

When I reply to this email, I get a delivery error and the mail doesn‘t go through. See an extract below.

I tried replying from the native app of the email provider as well as Apple Mail on Mac OS, but without success.

I‘ve used "Hide My Email" in the past and was able to reply to emails without any issues. The emails where sent properly and the correct "Hide My Email" address was shown as sender.

Any ideas?

<support_at_abc_com_67k97bzp9r4564_d1c8fb39@icloud.com>: host 
mx01.mail.icloud.com[17.57.156.24] said: 550 5.7.1 Delivery not authorized 
(in reply to end of DATA command) 
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message/delivery-status 
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Reporting-MTA: dns; mail-4316.xyz.com
X-Postfix-Queue-ID: 4JSLPQ2xdHz4wwck 
X-Postfix-Sender: rfc822; abc@xyz.com
Arrival-Date: Mon, 3 Jan 2022 16:12:42 +0000 (UTC) 

Final-Recipient: rfc822; support_at_abc_com_67k97bzp9r4564_d1c8fb39@icloud.com 
Original-Recipient: rfc822;support_at_abc_com_67k97bzp9r4564_d1c8fb39@icloud.com 
Action: failed 
Status: 5.7.1 
Remote-MTA: dns; mx01.mail.icloud.com 
Diagnostic-Code: smtp; 550 5.7.1 Delivery not authorized 
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