Certificate issue

When you're experiencing issues with an ACM certificate stuck in "Pending validation" status for CloudFront, there are several important factors to consider.

First, CloudFront specifically requires certificates to be in the US East (N. Virginia) region (us-east-1), so you're correct in requesting a new certificate in that region. However, even though the validation records might appear identical between regions, each certificate request generates unique validation records that must be properly set up.

The most common reasons for certificate validation failure include:

1. DNS Configuration Issues: Ensure that the CNAME records for validation are correctly set up in your DNS configuration. Even if they look the same as previous records, verify they match exactly what ACM is requesting for the us-east-1 certificate.

2. Nameserver Configuration: Verify that your domain is using the correct nameservers. If the nameservers configured at your domain registrar don't match the nameservers shown in your DNS hosting service (like Route 53), validation will fail.

3. CAA Records: Check if there are any Certification Authority Authorization (CAA) records that might be blocking certificate issuance for your domain.

4. Validation Timeout: ACM certificate requests that aren't validated within 72 hours will time out and fail. If this has happened, you'll need to delete the failed request and create a new one.

5. DNS Propagation: DNS changes can take time to propagate globally. You can verify the CNAME records are visible using tools like dig or nslookup.

6. DNS Record Conflicts: Having both NS records and CNAME records for the same name can create DNS resolution conflicts.

At this point, since your certificate validation has failed, I recommend:

1. Delete the failed certificate request in us-east-1
2. Create a new certificate request in us-east-1
3. Add the new CNAME validation records to your DNS configuration
4. Verify DNS resolution with nslookup or dig before proceeding

If the issue persists with a new certificate request, you may want to contact AWS Support for further assistance.
Sources
ACM certificate stuck in “Pending validation” despite correct DNS CNAMEs | AWS re:Post
ACM certificate stuck in “Pending validation” status despite correct DNS CNAME record in Route 53 | AWS re:Post
How long request for SSL certification takes? | AWS re:Post