@thewismit
It might be haproxy, dns by itself shouldn't cause this error.. Unless if its pointing to a wrong/different server/(caching)proxy..
If DNS is pointing to the cloudflare 'proxy', then you need to make sure that they have the proper certificate and encryption cipher options to accept the connection from the browser.. If DNS is pointing directly to the WAN ip, then it has to be haproxy that is sending the wrong allowable ciphers. Perhaps you could try with SSLlabs to see if/what ciphers are currently shown when visiting your wanip and/or domainname.?
Can you share the haproxy.cfg file perhaps? (with obfuscated ip/domain names)
Can you maybe share the domainname and your public ip? Or send me a PM, maybe i can see something hinky.?.