Multiple outbound calls from calling one time

Recently, every few days, calling a number will result in the person receiving multiple calls from us at the same time, up to the maximum limit my SIP trunking provider allows 8.

For example, I call a number, I hear on my sip phone the ringing sound and their voice mail at the same time,and if they pick up the phone, I hear their voice and their voicemail and they receive seven voice mails with no sound. I am at my whits end.

I am using pfsense for my router. I tried port forwarding ports 10,000-20,000 to FreePBX, accepting all communication from our providers SIP server IP & port mapping of 5060 ( so pfsense does not change the port number ) to no avail. The only fix I have found is restarting FreePBX. I would love it if someone could help.

We are here to help but you need to supply much more information.

System info, a trace (this will be a long one so use of both the Asterisk call flow and the SIP messaging would be a good place to start.