Nginx prevents more than one site from listening to 443 on IPV6, where to dig?

Question

Nginx

In general, having set up with the help of Benin's mother the support and operation of VPS on IPV6, I ran into the following jamb of work.
There is a conditionally pool of sites, and one of them prescribed the directive in the config

listen 443 ssl http2; 
 listen [::]:443 ssl http2 ipv6only=on;

And this site is the only one from the pool of sites and only works on V4 and V6
when you try to make a directive listen [::]:443 ssl http2 ipv6only=on;to other sites, Nginx swears for no
reason - they say it already exists in such and such a config.
When you try to go curl to other sites on V6 - the server gives the code 444 (empty response)
Question - where to dig?

Answer 1

According to the logic of things, primitively speaking, this parameter may not be specified in the host configuration (of a separate site), but in the server config. I don’t quite understand what kind of economy you have, but here I use nginx - I have a server config, and in the directory of each site there are virtual host configs ... I only specify certificates there, and accordingly the site works on http or on https. .. it’s not my topic at all, it’s probably impossible to misunderstand ((

Answer 2

this directive says whether to listen only to v6 on wildcard [::] or both v6 and v4
the question is, what do you want to achieve?)
if you want the server to listen to both 4 and 6 then write
listen [::]: 443 ssl http2;
if you want to listen only v6 then write
listen [::]:443 ssl http2 ipv6only=on;
in any of the configs and all of them will only listen to v6
nginx.org/en/docs/http/ngx_http_core_module.html#listen