Did you point the nameserver records at the Namecheap registrar to the Route53 hosted zone?
It sounds like maybe you haven't.
Once you do that, it could take up to a couple of days for everything to propogate.
Thanks - I had copied those in and they were essential. I hope that answer helps someone as I discovered it by accident.
The answer to my particular problem is that Namecheap use @ and www in the Host field for the apex domain and subdomain respectively. When I added the DNS ALIAS records in Namecheap's console I had entered the domain name (mydomain.com and www.mydomain.com ) rather than those placeholders.
Edited by: sevcon on Aug 3, 2021 8:51 AM
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