NTP does not synchronize time, what could be?

Question

Debian

The crux of the issue is that ntp is not seeing my ntp server.

systemctl status ntp 
error resolving pool 0.xxx.xxx.xxx: Name or service not know (-2) 
error resolving pool 1.xxx.xxx.xxx: Name or service not know (-2) 
error resolving pool 2.xxx.xxx.xxx: Name or service not know (-2) 
error resolving pool 3.xxx.xxx.xxx: Name or service not know (-2)

ntpdate -u xxx.xxx.xxx
Successfully fulfills and picks up the time, but does not synchronize it further.

timedatectl 
System clock synchronized: no
NTP service: inactive
RTC in local TZ : no

ntpq -pn 
delay 0.000 offset 0.000 jitter 0.000

What was I trying to do?
I tried to take regular pools by type: debian.pool.ntp.org
I tried to reinstall ntp itself, ntpdate
PS my dns acts as an ntp-server
In Google I didn’t find anything interesting, they are usually helped by stopping ntp and then picking up time from ntpdate, and I still have in the status writes that my server or address is unknown to him.
Although the ping goes.

Answer 1

He sees everything, he just can't tell. Set up DNS normally, or go straight for the IP, not the name.