Why is the site not accessible from www, where could there be an error in the nginx config?

Question

Nginx

Hello.
There is a local site, but it does not work if you open it from www in the url
site.com - www.site.com works - error
does not work What could be the problem? in the file /etc/hosts the site is specified like this nginx config

127.0.1.1 dcms.lo

server {
   listen 80;
   listen [::]:80;
 
   root /home/alex/mf/dcms/public;
 
   index index.php index.htm index.nginx-debian.html;
 
   server_name dcms.lo www.dcms.lo;
 
   location / {
     include  /etc/nginx/mime.types;
     try_files $uri $uri/ /index.php?$query_string;
   }
 
   location ~ \.php$ {
     include snippets/fastcgi-php.conf;
     fastcgi_pass unix:/run/php/php7.2-fpm.sock;
   }
 
   location /assets {
     alias /home/alex/mf/dcms/assets/;
     try_files $uri $uri =404;
   }
 
   location ~ /\.ht {
     deny all;
   }
 }

Answer 1

hosts
127.0.1.1 dcms.lo
127.0.1.1 www.dcms.lo

Answer 2

it's not about nginx show dns records of the domain

Answer 3

On the tracker, try two site addresses. First, with www, then without, and on statistics and graphs, you will see the difference and where the legs of the problem grow from.
Paste it into the field and start the analysis: www.host-tracker.com/ru/InstantCheck/Create/