#1 is still unknown.
It only affects some people, and I think there is actually a correlation to hiccups in the internet connection and this problem, but it isn't really clear yet how. Sorry, we'll continue investigating.
I can "reproduce" the disconnect issue on both Chrome and Firefox on my Android 6.0 tablet. This tablet only has WIFi interface (no mobile data as backup).
Game sends me to "Server connection was closed or could not be extablished." screen
right after I disable Wi-Fi.
Client obviously knows, that something is wrong (because of the error screen), so it could try to automatically reconnect the wss:// connection every second until it succeeds. This could be in the background completely invisible to a player. So after I enable Wi-Fi again the game would continue automatically.
I think that solving this absurd case will likely also solve the actual disconnects which people are reporting.
Let me know whether you can "reproduce" it by yourself. I can help with testing the potential solution if you can not.
EDIT: This websocket example survives even if I connect to a different Wi-Fi:
https://demo.kaazing.com/forex/