Firewall doesn't block other ports than 5060 and 5160

Hi guys!

If you change chan_sip to another port different than 5060 or 5160, firewall will allows you to register to the PBX, no mather if Responsive firewall is disabled, or the ip you are using to register is not whitelisted.

I just changed chan_sip to port 4399, and I was able to TRY to register an extension with my 4g cellphone network (ip is not whitelisted and responsive firewall is OFF)

[2020-08-04 22:49:42] NOTICE[13696]: chan_sip.c:29029 handle_request_register: Registration from '<sip:100001@mypbx.rocks>' failed for '186.111.156.138:52621' - Wrong password
[2020-08-04 22:49:42] NOTICE[13696]: chan_sip.c:29029 handle_request_register: Registration from '<sip:100001@mypbx.rocks>' failed for '186.111.156.138:52621' - Wrong password
[2020-08-04 22:49:43] NOTICE[13696]: chan_sip.c:29029 handle_request_register: Registration from '<sip:100001@mypbx.rocks>' failed for '186.111.156.138:52621' - Wrong password
 -- Remote UNIX connection
 -- Remote UNIX connection disconnected
[2020-08-04 22:49:48] NOTICE[13696]: chan_sip.c:29029 handle_request_register: Registration from '<sip:100001@mypbx.rocks>' failed for '186.111.156.138:52622' - Wrong password
[2020-08-04 22:49:48] NOTICE[13696]: chan_sip.c:29029 handle_request_register: Registration from '<sip:100001@mypbx.rocks>' failed for '186.111.156.138:52622' - Wrong password
[2020-08-04 22:49:48] NOTICE[13696]: chan_sip.c:29029 handle_request_register: Registration from '<sip:100001@mypbx.rocks>' failed for '186.111.156.138:52622' - Wrong password

If I revert the changes and I set chan_sip to 5160, I cannot register (I don't see any failed registrations attempts like I saw before)