caddy: access logging doesn't seem to be working

Dockerfile

FROM caddy:2.5.1-builder-alpine AS builder

RUN xcaddy build \
    --with github.com/mholt/caddy-ratelimit \
    --with github.com/caddyserver/transform-encoder
    
FROM caddy:2.5.1-alpine

COPY --from=builder /usr/bin/caddy /usr/bin/caddy

docker-compose.yml

version: "3.7"

services:
  caddy:
    image: caddy:1653111634
    container_name: caddy
    hostname: caddy
    restart: unless-stopped
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - /etc/localtime:/etc/localtime:ro
      - ./Caddyfile:/etc/caddy/Caddyfile:ro
      - ./config:/config
      - ./logs:/logs
      - $HOME/lego-certificates/certificates:/certs:ro
    env_file: .env

networks:
  default:
    name: $DOCKER_MY_NETWORK
    external: true

Caddyfile

(logging) {
	log {
		output file /logs/access.log {
			roll_size 10MiB
			roll_keep 5
			roll_keep_for 48h
		}
		# format transform "{common_log}"
		format transform "{request>remote_addr} - {request>user_id} [{ts}] {request>method} {request>uri} {request>proto} {status} {size} {request>headers}" {
			time_format "02/Jan/2006:15:04:05 -0700"
		}
	}
}

test.{$MY_DOMAIN} {
	import logging
	
	@internal-api {
		path /api/internal/*
		remote_ip {$SERVER_IP}
		header x-internal-api-key {$INTERNAL_AUTH_KEY}
	}

	handle @internal-api {
		reverse_proxy api:8000
	}
}

The file is never created. It doesn’t matter whether I create the logs directory or let the container create it. It doens’t matter what value format is.

Changing it to something /var/log/ also doesn’t help. Changing output to stdout sometimes works and sometimes doesn’t. I make sure I do docker-compose down and up each time I change any config.

What is weird is I have the exact similar config on another server (running Debian 11) where everything works. On my Ubuntu servers (20.04 and 22.04), the log files are never created. The docker engine is the same everywhere.

The caddy logs have no relevant information.

How do I debug this situation ? I can see the access logs on my api container and enabling debug in Caddy also shows the complete log.