In Elastix Polycom IP phone not hanging up when other party terminates call

when the other party terminates the call, my IP phones do not hang up. I can see the traffic stop by looking at the output of a tcpdump -nn host 192.168.1.99. I can see the instant I hang up the mobile phone. It stops alternating ports. I’m assuming I’m not still connected with my carrier, which is important to me. This seems to be only in a new installation. Had the same box in a different location, and I don’t think I had the same issue. Have experienced this talking to a mobile phone and the PaloSanto 877 number, on two different IP phones. Is there some hangup setting I can look at?

12:59:57.444011 IP 192.168.1.99.2244 > 192.168.1.101.13596: UDP, length 172
12:59:57.462497 IP 192.168.1.101.13596 > 192.168.1.99.2244: UDP, length 172
12:59:57.464507 IP 192.168.1.99.2244 > 192.168.1.101.13596: UDP, length 172
12:59:57.482057 IP 192.168.1.101.13596 > 192.168.1.99.2244: UDP, length 172
12:59:57.484005 IP 192.168.1.99.2244 > 192.168.1.101.13596: UDP, length 172
12:59:57.503915 IP 192.168.1.99.2244 > 192.168.1.101.13596: UDP, length 172
12:59:57.523802 IP 192.168.1.99.2244 > 192.168.1.101.13596: UDP, length 172
12:59:57.543769 IP 192.168.1.99.2244 > 192.168.1.101.13596: UDP, length 172
12:59:57.563804 IP 192.168.1.99.2244 > 192.168.1.101.13596: UDP, length 172
12:59:57.583771 IP 192.168.1.99.2244 > 192.168.1.101.13596: UDP, length 172

Are you using SIP or ZAP trunks ?

SIP. All SIP. Only one Trunk set.