WordPress in docker compose slow first response

Question

In a VPS I have created a structure using docker where there is an NGINX Proxy Manager to handle the incoming requests and with a docker-compose.yaml I have 5-6 simple sites (no eCommerce) running. My problem is that the site after a long period of let's say inactivity it is like it's sleeping. It takes much time to do the first "loading". After that, on any device/network, the site is loading normally. The docker-compose.yaml I am using is the following

version: "3.9"
services:
  db:
    image: mariadb:latest
    volumes:
    - db_data:/var/lib/mysql
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: arootpassword
      MYSQL_DATABASE: sitedb
      MYSQL_USER: asiteuser
      MYSQL_PASSWORD: asitepassword
    deploy:
      resources:
        limits:
          cpus: '0.5'
          memory: 300M
        reservations:
          cpus: '0.25'
          memory: 128M
    networks:
      - backend

  redis:
    image: 'redis:alpine'
    restart: always
    networks:
      - backend

  wordpress-site:
    depends_on:
    - db
    image: wordpress:php8.2-apache
    volumes:
    - wordpress_data:/var/www/html
    expose:
    - "80"
    restart: always
    environment:
      WORDPRESS_DB_HOST: db:3306
      WORDPRESS_DB_USER: asiteuser
      WORDPRESS_DB_PASSWORD: asitepassword
      WORDPRESS_DB_NAME: sitedb
    deploy:
      resources:
        limits:
          memory: 800M
        reservations:
          memory: 128M
    networks:
      - nginx-proxy
      - backend

volumes:
  db_data: {}
  wordpress_data: {}

networks:
  nginx-proxy:
    name: nginx-proxy
    external: true
  backend:
    external: false

While the NPM compose file I am using is the following

version: '3.8'
services:
  npm:
    image: 'jc21/nginx-proxy-manager:latest'
    restart: unless-stopped
    ports:
      - '80:80'
      # - '81:81'
      - '443:443'
    expose:
      - '81'
    volumes:
      - ./data:/data
      - ./letsencrypt:/etc/letsencrypt
    deploy:
      resources:
        limits:
          cpus: '0.50'
          memory: 200M
        reservations:
          cpus: '0.25'
          memory: 128M
networks:
  default:
    name: nginx-proxy
    external: true

Any ideas? Is there any kind of configuration that I could allow docker to use 100% of the host or something to increase the performance? Is healthcheck something that I should consider?