smartlink

I can't help with iPhone issue (if there is one), but I can tell you that you need to set up the router differently than I think you have described.  I've looked at this router's instructions and I see it supports UPnP.  SmartLink uses UPnP when it is available and that is definitely the way to go if you can.

The router's instructions describe how to turn UPnP on.  Once you've done that, you should go back to the SmartLink configuration and select "automatic" configuration.  This will send a UPnP request to the router which should open and forward the necessary ports.

All of this is assuming your router is the only router in  your LAN.  If your ISP gave you a router and you've put the R6220 router behind it (cascaded routers), some special steps will be needed.

You haven't said if you have tested the SmartLink connection from the radio using the "test" button.  If that works, then your ports are correctly forwarded and no additional changes are needed.  If that doesn't work, then there is no need to look elsewhere for a problem.  The "test" button tests the communication paths from the radio to the outside world and back.  If it doesn't work, nothing will work from the outside.