I have configured new extensions in the ISABEL PBX but the phone does not register, something curious is that if I go to Security / Firewalls / Firewall Rules the firewall appears deactivated, if I click on the activate button, immediately the phones are registered by a few seconds, but when finished updating, they get no registered again, but if I press the button again to deactivate the firewall, the extensions are registered again for a few seconds, I can even make a test call between them, but they come back to no registered again, this happens to me using sip protocol and iax2 in a local lan network