Transferred domain is stuck in TransferPeriod state

The "transferPeriod" status you're seeing is normal after a recent domain transfer and doesn't necessarily indicate that the transfer is incomplete. This status is typically applied for a set period (often 60 days) after a domain transfer as a security measure to prevent unauthorized transfers.

During this period, your domain is fully functional and under your control in AWS Route 53. The "transferPeriod" status doesn't prevent you from managing your domain or its DNS settings. However, it does restrict you from transferring the domain again until the period expires.

If you're having issues with certificate validation, it's likely not related to the "transferPeriod" status. Instead, it could be due to DNS propagation delays or incorrect DNS configuration. Here are some steps you can take:

1. Verify that you've created a new hosted zone in Route 53 for your domain.
2. Ensure all necessary DNS records are properly set up in this hosted zone.
3. Check that the nameservers (NS records) at your domain registrar match those provided by AWS Route 53.
4. Confirm that you've correctly set up the DNS records required for certificate validation.

If you've verified these points and are still experiencing issues, it may be worth contacting AWS Support for further assistance with your domain configuration and certificate validation process.

Unfortunately, there's no way to manually remove the "transferPeriod" status - it will automatically expire after the set period. This is a standard industry practice to protect against unauthorized domain transfers.
Sources
Route 53: Can't transfer out a domain to another domain | AWS re:Post
Migrated domain to AWS and DNS not working in many places | AWS re:Post