I'm having the same ports problem that you solved earlier in the article at this link:
https://community.checkpoint.com/t5/SMB-Gateways-Spark/3CX-Phone-System-behind-1450-Appliance/td-p/1...
The problem is that the original ports i.e. 5060-5061,5090-5091,9000-10999 are replaced by random ports.
My 3CX Phone System V15 installed on a Windows 10 Pro OS is not giving me the path to resolve the issue. I just understood that in the article posted on the forum, the 3CX phone system behind the 1450 Appliance was running on DEBIAN.
I cannot find in my 3CX V15 phone system the settings “With manual static NAT. »
So, I find that 3CX configuration settings differ from OS to OS.
I need your help to keep the original ports intact, i.e. the original ports 5060-5061,5090-5091,9000-10999 are no longer replaced by ports random.