What is the peculiarity of connecting a VoIP gateway with two FXS ports to Asterisk?

Question

Asterisk

Hello.
Faced the following problem:
Fanvil A2 ATA voice gateway and Asterisk (11.4.0) IP telephony server with FreePBX 2.11.0.36
Internal numbers are set on the server. For example, 126 and 127.
Two SIP lines can be configured on the gateway at once. We configure SIP1 to use the number 126 - everything is fine, registration is passing.
We configure SIP2 to use the number 127 - Unapplied status.
If you first set SIP2 to number 127, everything is fine. But as soon as I set up SIP1, SIP2 will stop working again.
In FreePBX number settings there is a PORT parameter with the following comment "Endpoint port number to use, usually 5060. Some 2 ports devices such as ATA may used 5061 for the second port." - I tried to specify port 5061 for the second number, respectively, at the station and at the gateway itself - registration still does not occur.
upd:
Settings on Fanvil:

Extensions settings via FreePBX:
128:
126:

Answer 1

Enable sip trace on the asterisk to understand what comes in and how the asterisk responds to it.