Wordpress Site Health errors from basic setup

Hi,

I have been experimenting with Traefik v2 for a while now trying to get a working version of Wordpress running using docker, nginx and php-fpm. After a lot of head-scratching and reading countless articles online I have decided to go back to basics.

I have created a Traefik docker container and a Wordpress container. I am using Traefik CLI only. The site installed ok and I can access it. It seems to work, however Site Health is reporting the errors shown in the screenshot.

Have I got something wrong in my configuration?

version: '3'

services:
  traefik-proxy:
    container_name: traefik-proxy
    image: traefik:v2.1
    command:
      - "--entrypoints.web.address=:80"
      - "--log.level=DEBUG"
      - "--log.filePath=./traefik.log"
      - "--log.format=json"
      - "--api.insecure=true"
      - "--providers.docker=true"
      - "--providers.docker.exposedByDefault=false"
      - "--providers.docker.network=traefik"

    ports:
      - "80:80"
      - "8080:8080"
    labels:
      - "traefik.http.routers.api.rule=Host(`traefik.docker.localhost`)"
      - "traefik.http.routers.api.entrypoints=web"
      - "traefik.http.routers.api.service=api@internal"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    networks:
      - traefik

networks:
  traefik:
    external: true
version: "3"

services:
  test_db:
    image: mariadb:10.5.1
    container_name: test_db
    volumes:
      - ./db_data:/var/lib/mysql:rw
    environment:
      MYSQL_ROOT_PASSWORD: "password"
      MYSQL_DATABASE: "wp_test"
      MYSQL_USER: "testadmin"
      MYSQL_PASSWORD: "admin"
    networks:
      - test_network

  test_wp:
    image: wordpress:5.3.2-php7.4
    container_name: test_wp
    volumes:
      - ./html:/var/www/html:rw
    environment:
      WORDPRESS_DB_HOST: test_db:3306
      WORDPRESS_DB_USER: "testadmin"
      WORDPRESS_DB_PASSWORD: "admin"
      WORDPRESS_DB_NAME: "wp_test"
    labels:
      - "traefik.enable=true"
      - "traefik.docker.network=traefik"
      - "traefik.http.routers.test_wp-http.entrypoints=web"
      - "traefik.http.routers.test_wp-http.rule=Host(`testdomain.com`, `www.testdomain.com`)"
    networks:
      - traefik
      - test_network

    depends_on:
      - test_db

volumes:
  db_data: {}
  html: {}

networks:
  traefik:
    external:
      name: traefik

  test_network:
    internal: true