SSL certificate

If the settings are OK, the verification will basically succeed within 72 hours.
https://docs.aws.amazon.com/acm/latest/userguide/troubleshooting-timed-out.html

Requests for ACM certificates time out if they are not validated within 72 hours. To correct this condition, open the console, find the record for the certificate, click the checkbox for it, choose Actions, and choose Delete. Then choose Actions and Request a certificate to begin again. For more information, see DNS validation or Email validation. We recommend that you use DNS validation if possible.