I need help or advice again. I have an app working on my iPhone in FMGo 15 which happily talks to the host over the local Wifi. I have set up the host with port forwarding and using the likes of DynDNS and it all works fine over 4G. I don't have much traffic as most of the work is done on the client collecting data. However there are times when i open up the app over 4G and it cannot see the host - (I have implemented a check script for this) and yet using a service I picked up from another discussion the port and host can be seen by the phone which means there is a reluctance for the filemaker host to respond to the 4G call. However if I manage to find a wifi hotspot my iPhone can once again connect and 4G continues to work after I have left the vicinity of the wifi. Now after every connection my script includes closing all the intermediary files (2 on the iPhone and 2 on the host) so it shouldn't have a residual link or is that the issue not that it makes any sense needing a foreign wifi to kick it on. Anyone got any thoughts about what I should try to get to the bottom of it?