Do you use something like fail2ban that could have locked you out?
You are right. It's fail2ban. This service is running. After stop it and make command 'iptables --flush' IPSConfig opens again.
In addition fail2ban blocks exactly port but not my or certain IP only. Because IPSConfig is not available from any hosts when blocked.
For now I exclude fail2ban from autostart.
But what do you suggest to me? Is it possible to get running fail2ban and workable IPSConfig?