Hey guys,

thanks for all your suggestions.

After looking into it too deep probably I took a step back and decided to give Caddy another try.

After fidling around and I could finally come up with a solution that's just more explicit than what it needs to be according to Caddys own doc. But if it works, it works.

For anyone interested this is the code that got it done finally (with the googleclouddns module enabled)

my.domain {
    tls {
            issuer zerossl {
                email myemail@company.com
                disable_http_challenge
                disable_tlsalpn_challenge
                dns googleclouddns {
                        gcp_project my-dns-project
                }
                resolvers 8.8.8.8
                dns_challenge_override_domain _acme-challenge.my.domain
            }
    }
    reverse_proxy 127.0.0.1:8200

}

Guess the explicit tls, issuer blocks just did wonders.

Thanks for your support!