I am trying to host a React app on AWS with a custom domain by following this tutorial (minus the continuous development stuff). So far I am able to visit my website from both the S3 bucket and the CloudFront endpoints. I have a domain on Route53 (we'll call it example.com) that I purchased a month or so ago and a hosted zone for it. My problem starts here: I am requesting an ACM certificate (on us-east-1) for example.com, www.example.com, and *.example.com and choosing to validate it through DNS. In the next page I am creating records for the 3 domain entries and I can see that they appear on the hosted zone records as CNAME's (only 2, though, as example.com and *.example.com are identical) but it still says: "Validation not complete". I've been all morning busy with this. I have tried clicking the create record buttons again, requesting more certificates, etc. I know this can take time but it's been 5 hours.
My issue was that the Name Servers under "Hosted zone details" were not the same as the ones in my registered domain. I believe this might have happened because I had to re-create the hosted zone. The first time I did what's detailed in the post it worked without issue, but that was when I was using the hosted zone that gets automatically generated when you purchase your first domain proof. I replaced the domain's NS's with the hosted zone's and re-requested a certificate. In around 5 minutes it was validated.