This has been a pretty big user issue for a long time. There needs to be better support for changing networks without the client simply disconnecting from the remote file.
This is extremely disruptive to users. When using FMGo and and the devices switch between wifi and wireless network data the solution fails. When using FMP and the wifi network changes the same issues. Web Direct, same thing. Same thing when a laptop that was remote comes back to LAN and gets hard wired and wifi turned off. These are real things that users have to deal with. This is in no way a graceful process either.
Current solution for me now is to tell users with mobile devices that they need turn off network data or wifi before using FMGo to maintain a single unchanging connection if possible. Mobile FMP is a more difficult task. There are plenty of applications that manage connections/credentials across a remote network change. This is also a big complaint I get from end users and they seem to expect something better. With more and more use of mobile and more use of mobile laptops by businesses this should really be something that gets addressed.