You can try using openssl s_client -connect domain:443 to help debug what the issue is. Without your domain it’s hard to guess what specifically is causing a TLS issue.
Where did you get your certs? Do they match exactly the domain you’re using? Are they expired or self signed? Are your details in the double curly brackets all correct?
You can try to use ssllabs, check cipher compatibility with browsers and such… though I think that requires things are working to a certain level first.