Inbound calls dropping after 30 seconds (don't believe it to be firewall related)

I have inbound calls dropping after 30 seconds and my SIP provider (Flowroute) is saying I have mismatched IPs in the contact portion of my invite causing the issue.

The invite header is showing my external IP while the contact is showing my internal IP of the PBX.

My IP settings inside of freepbx are:
NAT: Yes
Static IP: 12.xxx.xxx.xxx
Local Networks: 192.168.2.0/255.255.255.0

I setup my pfsense firewall exactly like Flowroute wants it.

Since I never asked a question, maybe that’s why no one is replying. How do I get the IPs to match?

HELP!

Hi jford, we had a similar issue that was caused by our firewall having the SIP ALG on. In case it´s on, you should try to disable and do some tests.

pfsense does not have this out of the box. you have to install their sipproxy for this to exist. I haven’t done it.