Contact:Public-IP VS Contact:Private-IP in '200 OK' Asterisk response to an INVITE

I have been having a lot of issues with dropped calls starting sometime after Asterisk 14.6, The only difference I see in the pcap dump files is that in Asterisk 14.6, when Asterisk is sent an INVITE, it responds with the Private IP-Address of the Asterisk Server in the Contact Header, while in Asterisk 15.1.2, 15.3 (The versions I have tested), the Public IP-Address of the Asterisk Server is in the Contact Header. These cases are ran with the same network/permissions/mirrored pjsip.conf files.

Does anyone have any ideas what would cause this? Was there a change made to Asterisk at some point after Version 14.6 that could cause this? or is there some setting in a different configuration file that could cause this?

Thank you,