Error 404 nginx on mydomain/nextcloud/index.php/apps/files/

Hi, i have a problem configuring nextcloud on my own lan server.

I’ve a server equipped with debian 9, nginx 1.10.3, and i’ve installed nextcloud.
Now, once completed the web config, it redirects me to :

https://mydomain/nextcloud/index.php/apps/files/ and it shows a 404 not found error.

I created an nginx config for nextcloud using the official nginx tutorial for using nextcloud in a subfolder of /var/www (mine is /var/www/nextcloud) :

upstream php-handler {
#server 127.0.0.1:9000;
server unix:/var/run/php/php7.0-fpm.sock;
 }

server {
    listen 80;
    listen [::]:80;
    server_name cloud.example.com;
    # enforce https
    return 301 https://$server_name$request_uri;
}

server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    server_name cloud.example.com;

# Use Mozilla's guidelines for SSL/TLS settings
# https://mozilla.github.io/server-side-tls/ssl-config-generator/
# NOTE: some settings below might be redundant
ssl_certificate /etc/ssl/nginx/cloud.example.com.crt;
ssl_certificate_key /etc/ssl/nginx/cloud.example.com.key;

# Add headers to serve security related headers
# Before enabling Strict-Transport-Security headers please read into this
# topic first.
#add_header Strict-Transport-Security "max-age=15768000; includeSubDomains; preload;";
add_header X-Content-Type-Options nosniff;
add_header X-XSS-Protection "1; mode=block";
add_header X-Robots-Tag none;
add_header X-Download-Options noopen;
add_header X-Permitted-Cross-Domain-Policies none;
add_header Referrer-Policy no-referrer;

# Remove X-Powered-By, which is an information leak
fastcgi_hide_header X-Powered-By;

# Path to the root of your installation
root /var/www/;

location = /robots.txt {
    allow all;
    log_not_found off;
    access_log off;
}

# The following 2 rules are only needed for the user_webfinger app.
# Uncomment it if you're planning to use this app.
# rewrite ^/.well-known/host-meta /nextcloud/public.php?service=host-meta
# last;
#rewrite ^/.well-known/host-meta.json
# /nextcloud/public.php?service=host-meta-json last;

# The following rule is only needed for the Social app.
# Uncomment it if you're planning to use this app.
# rewrite ^/.well-known/webfinger /nextcloud/public.php?service=webfinger last;

location = /.well-known/carddav {
  return 301 $scheme://$host/nextcloud/remote.php/dav;
}
location = /.well-known/caldav {
  return 301 $scheme://$host/nextcloud/remote.php/dav;
}

location /.well-known/acme-challenge { }

location ^~ /nextcloud {

    # set max upload size
    client_max_body_size 512M;
    fastcgi_buffers 64 4K;

    # Enable gzip but do not remove ETag headers
    gzip on;
    gzip_vary on;
    gzip_comp_level 4;
    gzip_min_length 256;
    gzip_proxied expired no-cache no-store private no_last_modified no_etag auth;
    gzip_types application/atom+xml application/javascript application/json application/ld+json application/manifest+json application/rss+xml application/vnd.geo+json application/vnd.ms-fontobject application/x-font-ttf application/x-web-app-manifest+json application/xhtml+xml application/xml font/opentype image/bmp image/svg+xml image/x-icon text/cache-manifest text/css text/plain text/vcard text/vnd.rim.location.xloc text/vtt text/x-component text/x-cross-domain-policy;

    # Uncomment if your server is build with the ngx_pagespeed module
    # This module is currently not supported.
    #pagespeed off;

    location /nextcloud {
        rewrite ^ /nextcloud/index.php$request_uri;
    }

    location ~ ^/nextcloud/(?:build|tests|config|lib|3rdparty|templates|data)/ {
        deny all;
    }
    location ~ ^/nextcloud/(?:\.|autotest|occ|issue|indie|db_|console) {
        deny all;
    }

    location ~ ^/nextcloud/(?:index|remote|public|cron|core/ajax/update|status|ocs/v[12]|updater/.+|ocs-provider/.+)\.php(?:$|/) {
        fastcgi_split_path_info ^(.+?\.php)(/.*)$;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
        fastcgi_param HTTPS on;
        #Avoid sending the security headers twice
        fastcgi_param modHeadersAvailable true;
        fastcgi_param front_controller_active true;
        fastcgi_pass php-handler;
        fastcgi_intercept_errors on;
        fastcgi_request_buffering off;
    }

    location ~ ^/nextcloud/(?:updater|ocs-provider)(?:$|/) {
        try_files $uri/ =404;
        index index.php;
    }

    # Adding the cache control header for js and css files
    # Make sure it is BELOW the PHP block
    location ~ \.(?:css|js|woff2?|svg|gif)$ {
        try_files $uri /nextcloud/index.php$request_uri;
        add_header Cache-Control "public, max-age=15778463";
        # Add headers to serve security related headers  (It is intended
        # to have those duplicated to the ones above)
        # Before enabling Strict-Transport-Security headers please read
        # into this topic first.
        # add_header Strict-Transport-Security "max-age=15768000;
        # includeSubDomains; preload;";
        add_header X-Content-Type-Options nosniff;
        add_header X-XSS-Protection "1; mode=block";
        add_header X-Robots-Tag none;
        add_header X-Download-Options noopen;
        add_header X-Permitted-Cross-Domain-Policies none;
        add_header Referrer-Policy no-referrer;

        # Optional: Don't log access to assets
        access_log off;
    }

    location ~ \.(?:png|html|ttf|ico|jpg|jpeg)$ {
        try_files $uri /nextcloud/index.php$request_uri;
        # Optional: Don't log access to other assets
        access_log off;
    }
}

}

How can i make the program fully working ? Thank you very much