Certbot out of sync with nginx

clerical error here: i do not know how i posted two copies of the same 'listen 443 ssl;' section of michaeljinks.com. there is only one such section on the system.

sigh.

anyhow, MikeMcQ posted a section:

server {
    listen 80;
    listen [::]:80;
    server_name michaeljinks.com;
    access_log /var/log/nginx/michaeljinks.ssl_access_log main;
    error_log /var/log/nginx/michaeljinks.ssl_error_log info;
    root /var/www/localhost/htdocs/;
    location /.well-known/acme-challenge/ {
        root /var/www/localhost/htdocs;       # Use different folder if you prefer
    }
    location / {
       return 301 https://$host$request_uri;
    }
}

(...as well as the ssl part)

on my host i have, in the main nginx.conf file:

      server {
              listen 80 default_server
              server_name _;
              return 301 https://$host$request_uri;
              access_log /var/log/nginx/redirect_ssl.access_log main;
              error_log /var/log/nginx/redirect_ssl.error_log info;
        }

...so is it correct to say that i don't need a "listen 80" for each domain? or, would that be incorrect, and i really do need to give each domain its own "listen 80"? (and might my "fix all 80" approach part of the proboem...?)