ICloud custom domain catch-all

I have added two custom domains to iCloud (both from same registrar) but I have some catch-all issues.

One domain is working as expected with catch-all. Tested random addresses and the end up in my inbox. This domain didn’t had any mailboxes before.

The other domain doesn’t work as expected, random addresses are working with catch-all, but two old mail accounts are getting rejected.

I’m not sure, but I’m suspecting this has something to do with the case in this article Apple - Catch-all

Describes that deleted email account will be rejected instead of forwarded.

Does anyone have any suggestions how to solve this?