Remote Login Error Using DuckDNS, LetsEncrypt and NGINX

I'm running a production system and have secure access to in remotely using DuckDNS, LetsEncrypt and NGINX. I've build a new development system on the same home network and generated a new DuckDNS domain name, new LetsEncrypt certificate, configued NGINX and created a new router port forward from 433 to my dev system port 443.

I can ping the new system both locally and remotely and have used nmap to ensure the dev system port 443 is open. When I attempt to gain remote access I get the following error message:

This site can’t be reached. The webpage at https://xxxxxxxx.duckdns.org/ might be temporarily down or it may have moved permanently to a new web address.
ERR_SSL_UNRECOGNIZED_NAME_ALERT                                                                                                                                                 

It appears from the error message that it is reaching my dev system but their is some type of name issue. I'm not familiar with debugging this issue and looking for some guidance or suggestions on how to isolate and resolve this issue. Any thoughts or pointers would be much appreciated.