Remote VoIP Connecting to PBX Behind XG

First let me say I have had our PBX and local VoIP phones running on the XG for 5 years with very little issues however I am really struggling with our other office and their remote phones. For the most part I have them working, but far from perfect. What I am experiencing is phones randomly dropping and then connecting back on their own, once again randomly. I have to be honest and I don't know why, when we moved from v.17 to v18 and the rules and NAT separated this has really screwed me. I use to read the logs and reference FW ID's, NAT IDs when troubleshooting but now those ID's do not make sense anymore, they don't reference correctly anymore so I am at a loss even trying to troubleshoot what a good VoIP connection looks like compared to one that has dropped. 

I don't know if its the port assignment, since we have 3 static external IP's and I use one as the alias for the VoIP setup but I really need help. I have been holding off asking for help because I am embarrassed I can't figure out the issue. I have watched every v18 NAT video, researched everything I can regarding remote phones but I don't know why I am struggling so much and I can't let it go cause I know there has to be something I am not doing correctly, because obviously the phones shouldn't be dropping then reconnecting randomly with no pattern. 



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[edited by: emmosophos at 7:24 PM (GMT -7) on 5 Oct 2022]