Nginx remembering old subdomain - nginx

Question

I am having a weird issue. My ubuntu server is still remembering an old subdomain, even though the configuration files is deleted, both symlink and the original one.
The nginx service is restarted, and the health is just fine as seen below:
website:/etc/nginx/sites-enabled# sudo nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful
Why on earth is the old subdomain still accessible? there is no specific DNS settings for the subdomain, all I have is
*.domain.com | ip
www.domain.com | ip
This is the contents of nginx:
website:/etc/nginx/sites-enabled# ls
- is empty
website:/etc/nginx/sites-available# ls
- is empty
Nginx conf:
events {
worker_connections 768;
# multi_accept on;
}
http {
##
# Basic Settings
##
sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 2048;
# server_tokens off;
# server_names_hash_bucket_size 64;
# server_name_in_redirect off;
include /etc/nginx/mime.types;
default_type application/octet-stream;
##
# SSL Settings
##
ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
ssl_prefer_server_ciphers on;
##
# Logging Settings
##
access_log /var/log/nginx/access.log;
error_log /var/log/nginx/error.log;
##
# Gzip Settings
##
gzip on;
# gzip_vary on;
# gzip_proxied any;
# gzip_comp_level 6;
# gzip_buffers 16 8k;
# gzip_http_version 1.1;
# gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;
##
# Virtual Host Configs
##
include /etc/nginx/conf.d/*.conf;
include /etc/nginx/sites-enabled/*;
}
I have tried to disable nginx caching, but still it's like its remembering the old subdomain somehow. Any experience on this?