Sorry I don't know then. Without some debug logs its uncertain what happens there. I need some info that is not anynomized so theres no mistakes due to wrong omissions.- Check your DNS, does "nslookup yoursubdomainname" really resolve to the IP address of the OPNsense?- If Yes, Whats the output of "curl -v subdomainname"- What do the debug logs show when you try to reach it?- Which kind of application is listening there? Is it a HTTP or HTTPS application. - If the application demands a HTTPS connection, did you enable "TLS Insecure Skip Verify" like I asked?- When you deactivate the handler for the subdomain AND disable "abort", do you at least see an empty webpage and the certificate?If its a very complex issue, you can also go to https://caddy.community and fill out their help template. Show your old nginx configuration, and your current Caddyfile. That way they can see if theres a mistake.
The tls server name is not always "opnsense.local". It is actually the SAN (subject alternative name) of the certificate you add into system - trust - authorities.