If you don’t specify handlers, we just forward TCP to your application as is. This is useful if you want to handle TLS termination yourself, for example.
(in this context as-is means “from fly-proxy”).
what’s your use-case for terminating TLS without the proxy_proto hander? You might find this thread useful if you need more information about our internal network.
With Caddy, try one of these non-standard proxy_proto listener modules (1, 2), if you aren’t already. Make sure to configure the module for either proxy_proto version v1 or v2 as approp (Fly supports both: tls + proxy_protocol How to set HTTP/2 ALPN? - #14 by jerome).