DPMA stops working

After fresh installation of DPMA on newly compiled Asterisk Digium phones does not discover DPMA server.

Asterisk 16.2.1 currently running on localhost (pid = 3092)
localhost*CLI> digium_phones show version
Digium Phone Module for Asterisk Version 16.0_3.5.0
localhost*CLI> digium_phones license status
OK, Valid product license found

DPMA server is being discovered by phones only short amount of time after i reboot it, but then it’s like stopping to work.
Firewall is off, Selinux is in permissive mode.

[root@localhost asterisk]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:firewalld(1)

Nmap from different Unix device from the same network shows:

Starting Nmap 6.40 ( http://nmap.org ) at 2019-03-12 14:22 EET
Nmap scan report for 10.0.0.3
Host is up (0.0000020s latency).
Not shown: 994 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
1720/tcp open  H.323/Q.931
2000/tcp open  cisco-sccp
3306/tcp open  mysql
5060/tcp open  sip

Output of netstat command:

[root@localhost asterisk]# netstat -tulpn
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 0.0.0.0:2000            0.0.0.0:*               LISTEN      3092/asterisk
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      2963/sshd
tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN      2993/sendmail: acce
tcp        0      0 0.0.0.0:5060            0.0.0.0:*               LISTEN      3092/asterisk
tcp6       0      0 :::80                   :::*                    LISTEN      2961/httpd
tcp6       0      0 :::22                   :::*                    LISTEN      2963/sshd
udp        0      0 0.0.0.0:5060            0.0.0.0:*                           3092/asterisk
udp        0      0 0.0.0.0:38959           0.0.0.0:*                           2672/avahi-daemon:
udp        0      0 0.0.0.0:5353            0.0.0.0:*                           2672/avahi-daemon:
udp        0      0 127.0.0.1:323           0.0.0.0:*                           2718/chronyd
udp        0      0 0.0.0.0:4520            0.0.0.0:*                           3092/asterisk
udp        0      0 0.0.0.0:4569            0.0.0.0:*                           3092/asterisk
udp        0      0 0.0.0.0:2727            0.0.0.0:*                           3092/asterisk
udp        0      0 0.0.0.0:51923           0.0.0.0:*                           3092/asterisk
udp        0      0 0.0.0.0:5000            0.0.0.0:*                           3092/asterisk
udp6       0      0 ::1:323                 :::*                                2718/chronyd
udp6       0      0 :::47511                :::*                                3092/asterisk

Asterisk is compiled on Centos 7

What can cause this issues?