OMNA camera not responding

I have iPad mini on iOS 10.3.3 as home hub for my OMNA camera. I could not view th camera with my iPhone 7 when it's out of wifi, ie away from home. It would show a still pic of what's captured and then loading and shows not responding. I tried using the dlink OMNA app and that one doesn't connect at all. Just keeps spinning. Everything works on wifi.

All firmwares are upto date

how to get it worki