Magento 2: Slash as Category URL Suffix Gives 404 Error

We are developing a new Magento 2 website for a client who is currently using a Magento 1 website. All their category URLs end with a forward slash ("/"), but this doesn't work in Magento 2.

In Magento 2, when I set a forward slash as the Category URL Suffix, all category pages show a 404 Not Found page. Using something like "a/" doesn't work either. I've also tried to reindex the indexes manually, but that doesn't do the trick.

Does anybody has a Magento 2 website where this works as expected?

Edit: added nginx config

For nginx we're using a slightly adjusted version of the sample config. When the suffix is set to a forward slash, Magento shows it's own 404 page so I guess the problem is within Magento – not in the nginx config. But maybe I'm wrong, so here's the config:

server {
    *listen & server name*

    # Set Mage root
    set                                 $mage_root /var/www/domains/*domain*;
    root                                $mage_root/pub;

    # Some general settings applying to all locations
    index                               index.html index.php; ## Allow a static html file to be shown first
    autoindex                           off;
    charset                             off;

    add_header                          'X-Content-Type-Options' 'nosniff';
    add_header                          'X-XSS-Protection' '1; mode=block';

    location /setup {
        *setup folder rules*
    }

    location /update {
        *update folder rules*
    }

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

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

        alias                           $mage_root/pub;
        add_header                      X-Frame-Options     "SAMEORIGIN";
    }

    location /static/ {
        if ($mage_mode = "production") {
            expires                     max;
        }

        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 $request_filename) {
                rewrite                 ^/static/(version\d*/)?(.*)$ /static.php?resource=$2 last;
            }
        }

        location ~* \.(zip|gz|gzip|bz2|csv|xml)$ {
            add_header                  Cache-Control       "no-store";
            add_header                  X-Frame-Options     "SAMEORIGIN";
            expires                     off;

            if (!-f $request_filename) {
               rewrite                  ^/static/(version\d*/)?(.*)$ /static.php?resource=$2 last;
            }
        }

        if (!-f $request_filename) {
            rewrite                     ^/static/(version\d*/)?(.*)$ /static.php?resource=$2 last;
        }

        add_header                      X-Frame-Options     "SAMEORIGIN";
    }

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

        add_header                      X-Frame-Options "SAMEORIGIN";
    }

    ## These locations should be protected
    location /media/customer/           { deny all; }
    location /media/downloadable/       { deny all; }
    location /media/import/             { deny all; }
    location ~ cron\.php                { deny all; }

    location  /. {                                          ## Disable .htaccess and other hidden files
        return                          404;
    }

    location ~ (index|get|static|report|404|503)\.php$ {    ## Execute PHP scripts
        try_files                       $uri =404;

        expires                         off;                ## Do not cache dynamic content

        fastcgi_pass                    php7-0;

        proxy_read_timeout              600s;
        proxy_connect_timeout           600s;
        fastcgi_connect_timeout         600s;
        fastcgi_read_timeout            600s;

        fastcgi_param                   PHP_FLAG            "session.auto_start=off \n suhosin.session.cryptua=off";
        fastcgi_param                   PHP_VALUE           "memory_limit=256M \n max_execution_time=600";
        fastcgi_param                   MAGE_MODE           $mage_mode;
        fastcgi_param                   MAGE_RUN_CODE       $mage_code;
        fastcgi_param                   MAGE_RUN_TYPE       $mage_type;

        fastcgi_index                   index.php;
        fastcgi_param                   SCRIPT_FILENAME     $document_root$fastcgi_script_name;

        include                         fastcgi_params;     ## See /etc/nginx/fastcgi_params
    }

    location ~* ^.+\.php$ {
        return                          404;
    }
}

Edit2: added setting examples

Platform:                                           Magento 1   Magento 2
-----------------------
Category suffix set to: Gives:
""                      domain.tld/category         Works       Works
".html"                 domain.tld/category.html    Works       Works
"/"                     domain.tld/category/        Works       Doesn't work (404 page)