Wordpress returns "The link you followed has expired" error page whenever I add a new site, add a user etc

I have a Wordpress Multisite (subdomains) instance running on a VPS which seems to be working as expected a part from the fact whenever I add a user or add a site a "The link you followed has expired" page is returned and something happens.

I use Nginx and php7.2-fpm.

Here the config file:

server {
        listen 80;
        server_name www.domain.name domain.name *.domain.name;

        return 301 https://www.domain.name$request_uri;
}

server {
        listen 443 ssl;
        server_name domain.name;

        ssl_certificate /etc/letsencrypt/live/domain.name/fullchain.pem;
        ssl_certificate_key /etc/letsencrypt/live/domain.name/privkey.pem;
        include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
        ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot

        return 301 https://www.domain.name$request_uri;
}

server {
        listen 443 ssl;
        server_name www.domain.name;

        root /var/www/wordpress;

    access_log /var/log/nginx/domain.name.access.log;
    error_log /var/log/nginx/domain.name.error.log;

        ssl_certificate /etc/letsencrypt/live/domain.name/fullchain.pem;
        ssl_certificate_key /etc/letsencrypt/live/domain.name/privkey.pem;
        include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
        ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot

    include global/common.conf;

    # WORDPRESS : Rewrite rules, sends everything through index.php and keeps the appended query string intact
    location / {
            try_files $uri $uri/ /index.php?q=$uri$args;
    }

    # SECURITY : Deny all attempts to access PHP Files in the uploads directory
    location ~* /(?:uploads|files)/.*\.php$ {
            deny all;
    }
    # REQUIREMENTS : Enable PHP Support
    location ~ \.php$ {
        # SECURITY : Zero day Exploit Protection
            try_files $uri =404;
            # ENABLE : Enable PHP, listen fpm sock
            fastcgi_split_path_info ^(.+\.php)(/.+)$;
            fastcgi_pass unix:/var/run/php/php7.2-fpm-www.sock;
            fastcgi_index index.php;
            include fastcgi_params;
            fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    }
    # PLUGINS : Enable Rewrite Rules for Yoast SEO SiteMap
    rewrite ^/sitemap_index\.xml$ /index.php?sitemap=1 last;
    rewrite ^/([^/]+?)-sitemap([0-9]+)?\.xml$ /index.php?sitemap=$1sitemap_n=$2 last;
}

global/commonf.conf:

# Global configuration file.
# ESSENTIAL : Configure Nginx Listening Port
listen 80;
# ESSENTIAL : Default file to serve. If the first file isn't found, 
index index.php index.html index.htm;
# ESSENTIAL : no favicon logs
location = /favicon.ico {
    log_not_found off;
    access_log off;
}
# ESSENTIAL : robots.txt
location = /robots.txt {
    allow all;
    log_not_found off;
    access_log off;
}
# ESSENTIAL : Configure 404 Pages
error_page 404 /404.html;
# ESSENTIAL : Configure 50x Pages
error_page 500 502 503 504 /50x.html;
    location = /50x.html {
        root /usr/share/nginx/www;
    }
# SECURITY : Deny all attempts to access hidden files .abcde
location ~ /\. {
    deny all;
}
# PERFORMANCE : Set expires headers for static files and turn off logging.
location ~* ^.+\.(js|css|swf|xml|txt|ogg|ogv|svg|svgz|eot|otf|woff|mp4|ttf|rss|atom|jpg|jpeg|gif|png|ico|zip|tgz|gz|rar|bz2|doc|xls|exe|ppt|tar|mid|midi|wav|bmp|rtf)$ {
    access_log off; log_not_found off; expires 30d;
}

I ahve tried to find a solution online but I can't find anything. Thanks for the help!