Caddy getting LE certificate through ALPN even with TLS client auth enabled

1. The problem I’m having:

I am attempting to set Caddy with TLS Client Auth, but also have it get a Letsencrypt certificate via ALPN.

I don’t really have a problem, as it just works, isn’t TLS Client Auth supposed to make the ALPN check fail? HTTP-01 is disabled, port 80 is firewalled. Am I just ignorant about how it should work or is there any tunable for this? I wish to know why it succeded and how to make it fail (not that I am stupid, I just wish to know what allowed it to succeed).

TIA!

2. Error messages and/or full log output:

"challenge_type":"tls-alpn-01","ca":"https://acme-staging-v02.api.letsencrypt.org/directory"}

3. Caddy version:

2.10.0

4. How I installed and ran Caddy:

apt repo

a. System environment:

b. Command:

PASTE OVER THIS, BETWEEN THE ``` LINES.
Please use the preview pane to ensure it looks nice.

c. Service/unit/compose file:

PASTE OVER THIS, BETWEEN THE ``` LINES.
Please use the preview pane to ensure it looks nice.

d. My complete Caddy config:


This is mostly a test caddyfile, some things may not make much sense, I am just test-driving TLS Client auth, I redacted the  server's IP and the domain names.

{
auto_https disable_redirects
order abort before handle
}



https://PLAIN IP ADDRESS:443  {

        log syslog {
        output file /var/log/caddy/sys.log {
        mode 660
        roll_size 100MiB
        roll_keep 100
        roll_keep_for 30d
        }
	format console
        level info
       	}
	}


https://DOMAIN NAME:443 {

	tls { 
	protocols  tls1.3
        client_auth {
        mode require_and_verify
	trust_pool file {
	pem_file  /ca/cert_name.crt	
        }
	}
	}

	respond / "root"
		
	handle /cert {
	respond "handler"
	}
	
	
	


	log certlog {
	output file /var/log/caddy/cert.log {
	mode 660
	roll_size 100MiB
	roll_keep 100
	roll_keep_for 30d
	#roll_local_time 23:59
	}
	format console
	level debug
	}
}

5. Links to relevant resources:

Do the Caddy logs (debug mode enabled) give any clue? What do they say?