nginx - browser can't stop directing to https? - ssl

Question

Why nginx keep on directing without instructions?
I followed this guide to redirect port 80 to 3000:
server {
listen 80;
server_name example.co.uk www.example.co.uk;
location / {
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header Host $http_host;
proxy_pass http://127.0.0.1:3000;
}
}
It worked fine. Then I tried to roll back as before, and it just keeps on redirecting to https!
I even have removed nginx, but the browser is still redirecting to https! Why? What have done wrong? How can I fix it?
Any ideas?
This was the config before I tried on the redirect thingy:
server {
listen 80;
server_name example.co.uk www.example.co.uk;
return 301 https://$host$request_uri;
}
server {
# listen 80;
listen 433 ssl;
server_name example.co.uk www.example.co.uk;
ssl on;
ssl_certificate /etc/letsencrypt/live/example.co.uk/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/example.co.uk/privkey.pem;
#charset koi8-r;
#access_log logs/host.access.log main;
location / {
root /usr/share/nginx/html;
index index.html index.htm;
}
location ~ /.well-known {
allow all;
}
the HTTPS was working fine to before that.
EDIT:
I have re-installed nginx and tested it with nginx -t:
$ sudo nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful