Docker + Nginx + Several sites with reverse proxy; directory issue

I just configured my server to multi-site revproxy using docker external network and configured my revproxy nginx container to work with fastcgi. Right now, for testing purposes, one of the sites is working, but it seems that the nginx for the website container does not correctly figure out the path for laravel index file and only provides me with the default "Welcome nginx" page.

I would be very grateful for any help.

My Dockerfile for revproxy container

FROM nginx:alpine

EXPOSE 80/tcp
EXPOSE 443/tcp

CMD ["/bin/sh", "-c", "exec nginx -g 'daemon off;';"]
WORKDIR /var/www

docker-compose for revproxy container

version: '3.8'
services:
  nginx-proxy:
    build: ./
    container_name: nginx-proxy
    ports:
      - 80:80
      - 443:443
    volumes:
      - ./default.conf:/etc/nginx/conf.d/default.conf
      - /var/www:/var/www/html
      - ./backend-not-found.html:/var/www/html/backend-not-found.html
      - ./certs:/etc/nginx/certs:ro
    networks:
      - proxy
    restart: always

networks:
  proxy:
    external:
      name: nginx-proxy

nginx.conf file for revproxy container

server {
    listen       80;
    server_name  site.com;

    charset UTF-8;
    
    root /var/www/html/laravel/public;

    error_page 404 /backend-not-found.html;
    location = /backend-not-found.html {
        allow all;
    }

    location ~ \.php$ {
        resolver 127.0.0.11;
        set $upstream laravel-app:9000;
        # nginx will now start if host is not reachable
        fastcgi_pass    $upstream; 
        try_files $uri =404;
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
    }
    location / {
        resolver 127.0.0.11;
        set $upstream http://laravel-nginx:80;
        # nginx will now start if host is not reachable
        proxy_pass    $upstream;
        try_files $uri $uri/ /index.php?$query_string;
        gzip_static on;
    }
}
# Default
server {
    listen 80 default_server;

    server_name _;
    root /var/www/html;

    charset UTF-8;

    error_page 404 /backend-not-found.html;
    location = /backend-not-found.html {
        allow all;
    }
    location / {
        return 404;
    }

    access_log off;
    log_not_found off;
    error_log /var/log/nginx/error.log error;
}

And docker-compose file for website container

version: '3.8'
services:

  #PHP Service
  app:
    build:
      args:
        user: alex
        uid: 1000
      context: ./
      dockerfile: Dockerfile
    container_name: ${APP_NAME}-app
    restart: always
    tty: true
    working_dir: /var/www
    ports:
      - 9000:9000
    links:
      - db
    volumes:
      - ./:/var/www
      - ./docker-compose_configs/php/custom.ini:/usr/local/etc/php/conf.d/custom.ini
    networks:
      - proxy
      - app-network

  #Nginx Service
  nginx:
    image: nginx:alpine
    container_name: ${APP_NAME}-nginx
    restart: always
    tty: true
    ports:
      - 8080:80
    restart: always
    volumes:
       - ./:/var/www/html
    networks:
      - proxy
      - app-network
    depends_on:
      - app
    links:
      - app


  #MySQL Service
  db:
    image: mysql:latest
    container_name: ${APP_NAME}-db
    restart: unless-stopped
    tty: true
    ports:
      - 3306:3306
    environment:
      MYSQL_DATABASE: ${DB_DATABASE}
      MYSQL_ROOT_PASSWORD: ${DB_PASSWORD}
      MYSQL_PASSWORD: ${DB_PASSWORD}
      MYSQL_USER: ${DB_USERNAME}
      SERVICE_TAGS: dev
    networks:
      - app-network
    volumes:
      - dbdata:/var/lib/mysql
      - ./docker-compose_configs/mysql/my.cnf:/etc/mysql/my.cnf


  #PhpMyAdmin
  phpmyadmin:
    image: phpmyadmin/phpmyadmin
    container_name: ${APP_NAME}-pma
    environment:
      PMA_HOST: db
      PMA_ARBITRARY: 1
      UPLOAD_LIMIT: 400M
    restart: always
    networks:
      - app-network
    ports:
      - 8081:80
    depends_on:
      - nginx
      - db

  #elasticsearch
  elasticsearch:
    image: elasticsearch:7.12.1
    container_name: ${APP_NAME}-elasticsearch
    volumes:
      - elasticsearch-data:/usr/share/elasticsearch/data
    environment:
      - discovery.type=single-node
      - cluster.routing.allocation.disk.threshold_enabled=false
      - bootstrap.memory_lock=true
      - "ES_JAVA_OPTS=-Xms512m -Xmx512m"
    ulimits:
      memlock:
        soft: -1
        hard: -1
    ports:
      - "9200:9200"
    networks:
      - app-network
    depends_on:
      - db

#Docker Networks
networks:
  app-network:
    name: ${APP_NAME}-network
    driver: bridge
  proxy:
    external:
      name: nginx-proxy

#Volumes
volumes:
  dbdata:
    driver: local
  elasticsearch-data:
    driver: local