Why doesn't open server want to work with DNS?

Question

Domain Name System

There is an Open Server on which there are about 5 sites.
When they are registered in the hosts file, then everything is OK, I freely connect to them from the local network.
But when I want to use my DNS server, the sites stop loading.
As far as I understand, the hosts file along with ip still throws up the domain name?
And the DNS server only converts to ip and, for example, when I enter the site name mySite-1, Open Server receives only ip - 10.0.0.2 and does not know what to open? Or am I wrong? How to make DNS work?

Answer 1

To get started, check the DNS from any PC on the network with the command
nslookup {YOUR_DOMAIN} {IP_ADDRESS_DNS_SERVER}
For example

andres-MacBook-Pro:~ andre$ nslookup mail.ru 1.1.1.1
Server:		1.1.1.1
Address:	1.1.1.1#53

Non-authoritative answer:
Name:	mail.ru
Address: 94.100.180.201
Name:	mail.ru
Address: 217.69.139.200
Name:	mail.ru
Address: 94.100.180.200
Name:	mail.ru
Address: 217.69.139.202

Answer 2

Everything!!! configured, reinstalled Open Server to a newer one and it all worked!!! Hooray!!