Line6 should turn its attention to tone preset storing system. As it seems to me after I have tried all sugessions, some tones presets, that stored in cloud, during uploading to device in 100% occasions leads to lost connection. I think that for unknown reasons tone preset may be corrupted during upload/download/editing or changing Amplifi Remote version.
For example you can try preset with name "OS Riff1" in My Tones of my account. It always leads to drop remote App connection.