Certificates between domains are confused in NGINX, what to do?

Question

Nginx

Greetings!
Recently, there have been misunderstandings with SSL and NGINX: certificates are being confused with each other. There are many domains on the server (500+). If earlier it showed that the certificate was from the wrong domain (for example, going to test.ru it showed that the certificate belongs to test1.ru) and everything was solved by removing the test1.ru certificate, now everything has gone completely to a standstill, it gives: "Error when establishing a secure connection." without any additional information.
The syntax is normal (nginx -t), visually I also run through it - everything is ok (although I might miss something with such a volume). Please tell me which way to dig. Thank you.

Answer 1

To begin with, attach configs to the question, telepaths are on vacation.
If nginx is 1.9 and higher, the -T option has appeared there, which allows you to display the final config collected from all include. It is possible to look, what config turns out as a result for . domain.

Answer 2

nginx -V
The output should read
If not, then the first available certificate will be used.
nginx.org/ru/docs/http/configuring_https_servers.html