allworx reach Iphone5 won't register unless in home office

[rjsmith66]

We put in an allwors 6x several months ago with the reach feature enabled.

All of our android phones work flawlessly whether on office wifi, cellular network or any wifi network.

All of our users with Iphone 5 work perfectly when in the home office connected to our local wifi. If they are on ANY OTHER network (cellular or wifi) they try to register and then error out with this error: " The Allworx Server is reachable but phone can't register with SIP (TCP port 5060 for LAN 5060 for WAN).

Those ports are open on the 6X - not to mention they have to be because it works perfectly on our wifi network in this office. Also I will re-mention that androids work perfectly no matter where they are so it's some strange I phone issue.

These ports are listed under default route as being open:
Ports:
2088 (UDP)
5060 (UDP)
5060 (TCP)
8081 (TCP)
15000-15511 (UDP)

Any suggestions would be greatly appreciated.