It may be possible that your app is sending a invalid parameter such as a number versus a string.
Alternately, the custom app may be sending sequential commands too quickly.
In both cases, the camera should theoretically reject the command and NOT shut down. However, if there is a small bug in the API, the could could unexpectedly shut down.
For example, if you set options sequentially, there is a bug that causes the command to fail. I have seen API bugs that cause the camera to shutdown, but this is more common on the SC2. In general, the V and Z1 seem to be more forgiving of errors. However, it’s possible that an API command on the V is causing it to shutdown.
Suggest you attach a debug console to your custom app on the tablet and look for an error immediately prior to the camera shutting down.
Also, if you can guess what command is being sent, you can try just those commands.