Ok .We manage client's wan router. Zultys provided us a list of ports to open for the phone system to work. We did that. They asked us to route fqdn to the phone ip. Did that by using dns routing. Ip host fqdn host IP address.
Now, they their phone app is working from everywhere else apart from the client's wifi, which is odd, as their wifi public IP address is same as the public IP assigned to their wan interface. They are saying that traffic coming from fqdn is not going back to their pbx. But we already created a DNS record pointing to the IP address provided by them. I'll share the configuration and the pdf file mentioning their requirements.
