Magento 2.x 404 ressources loading issue

Question

The issue is that after upgrading to a newer version of Magento suddenly all ressources which are being loaded over the /pub/static/... suddenly failed because there were being fetched as /pub/static/version123123123<- the number is random. Upon googling for quite some time and playing around with the nginx config we've managed that the version was removed from the requesting URL for the frontend. But when I go to the checkout, or try to log in into the backend, the same issue occurs again. Some files are being requested with the version in the URL and are returning a 404 not found which results with the website being completely without any css/js ressources.

Our nginx config:

server {
    listen 80;
    listen [::]:80;

    # SSL configuration
    #
    # listen 443 ssl default_server;
    # listen [::]:443 ssl default_server;
    #
    # Note: You should disable gzip for SSL traffic.
    # See: https://bugs.debian.org/773332
    #
    # Read up on ssl_ciphers to ensure a secure configuration.
    # See: https://bugs.debian.org/765782
    #
    # Self signed certs generated by the ssl-cert package
    # Don't use them in a production server!
    #
    # include snippets/snakeoil.conf;

    root /var/www/html;

    server_name NAME OF SERVER;

    index index.php;
    autoindex off;
    charset UTF-8;
    error_page 404 403 = /errors/404.php;
    #add_header "X-UA-Compatible" "IE=Edge";

    # PHP entry point for setup application
    location ~* ^/setup($|/) {
        root /var/www/html;
        location ~ ^/setup/index.php {
            fastcgi_pass   fastcgi_backend;

            fastcgi_param  PHP_FLAG  "session.auto_start=off \n suhosin.session.cryptua=off";
            fastcgi_param  PHP_VALUE "memory_limit=768M \n max_execution_time=600";
            fastcgi_read_timeout 600s;
            fastcgi_connect_timeout 600s;

            fastcgi_index  index.php;
            fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
            include        fastcgi_params;
        }

        location ~ ^/setup/(?!pub/). {
            deny all;
        }

        location ~ ^/setup/pub/ {
            add_header X-Frame-Options "SAMEORIGIN";
        }
    }

    # PHP entry point for update application
    location ~* ^/update($|/) {
        root /var/www/html;

        location ~ ^/update/index.php {
            fastcgi_split_path_info ^(/update/index.php)(/.+)$;
            fastcgi_pass   fastcgi_backend;
            fastcgi_index  index.php;
            fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
            fastcgi_param  PATH_INFO        $fastcgi_path_info;
            include        fastcgi_params;
        }

        # Deny everything but index.php
        location ~ ^/update/(?!pub/). {
            deny all;
        }

        location ~ ^/update/pub/ {
            add_header X-Frame-Options "SAMEORIGIN";
        }
    }

    location / {
        try_files $uri $uri/ /index.php$is_args$args;
    }

    location /pub/ {

        location ~ ^/pub/media/(downloadable|customer|import|theme_customization/.*\.xml) {

            deny all;
        }
        alias /var/www/html/pub/;
        add_header X-Frame-Options "SAMEORIGIN";

        location ~ ^/pub/static/version {

            rewrite ^/pub/static/(version\d*/)?(.*)$ /pub/static/$2 last;
        }
    }

    location /static/ {
        # Uncomment the following line in production mode
        # expires max;

        # Remove signature of the static files that is used to overcome the browser cache
        location ~ ^/static/version {
            rewrite ^/static/(version\d*/)?(.*)$ /static/$2 last;
        }

        location ~* \.(ico|jpg|jpeg|png|gif|svg|js|css|swf|eot|ttf|otf|woff|woff2)$ {
            add_header Cache-Control "public";
            add_header X-Frame-Options "SAMEORIGIN";
            expires +1y;

            if (!-f $request_filename) {
                rewrite ^/static/?(.*)$ /static.php?resource=$1 last;
            }
        }
        location ~* \.(zip|gz|gzip|bz2|csv|xml)$ {
            add_header Cache-Control "no-store";
            add_header X-Frame-Options "SAMEORIGIN";
            expires    off;

            if (!-f $request_filename) {
            rewrite ^/static/?(.*)$ /static.php?resource=$1 last;
            }
        }
        if (!-f $request_filename) {
            rewrite ^/static/?(.*)$ /static.php?resource=$1 last;
        }
        add_header X-Frame-Options "SAMEORIGIN";
    }

    location /media/ {
        try_files $uri $uri/ /get.php$is_args$args;

        location ~ ^/media/theme_customization/.*\.xml {
            deny all;
        }

        location ~* \.(ico|jpg|jpeg|png|gif|svg|js|css|swf|eot|ttf|otf|woff|woff2)$ {
            add_header Cache-Control "public";
            add_header X-Frame-Options "SAMEORIGIN";
            expires +1y;
            try_files $uri $uri/ /get.php$is_args$args;
        }
        location ~* \.(zip|gz|gzip|bz2|csv|xml)$ {
            add_header Cache-Control "no-store";
            add_header X-Frame-Options "SAMEORIGIN";
            expires    off;
            try_files $uri $uri/ /get.php$is_args$args;
        }
        add_header X-Frame-Options "SAMEORIGIN";
    }

    location /media/customer/ {
        deny all;
    }

    location /media/downloadable/ {
        deny all;
    }

    location /media/import/ {
        deny all;
    }

    # PHP entry point for main application
    location ~ (index|get|static|report|404|503)\.php$ {
        try_files $uri =404;
        fastcgi_pass   fastcgi_backend;
        fastcgi_buffers 1024 4k;

        fastcgi_param  PHP_FLAG  "session.auto_start=off \n suhosin.session.cryptua=off";
        fastcgi_param  PHP_VALUE "memory_limit=768M \n max_execution_time=18000";
        fastcgi_read_timeout 600s;
        fastcgi_connect_timeout 600s;

        fastcgi_index  index.php;
        fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
        include        fastcgi_params;
    }

    gzip on;
    gzip_disable "msie6";

    gzip_comp_level 6;
    gzip_min_length 1100;
    gzip_buffers 16 8k;
    gzip_proxied any;
    gzip_types
        text/plain
        text/css
        text/js
        text/xml
        text/javascript
        application/javascript
        application/x-javascript
        application/json
        application/xml
        application/xml+rss
        image/svg+xml;
    gzip_vary on;

    # Banned locations (only reached if the earlier PHP entry point regexes don't match)
    location ~* (\.php$|\.htaccess$|\.git) {
        deny all;
    }


}