[General Maximus]

I'll keep a many-years-long-story and summarise by saying that the shubs don't work very well and they aren't proper routers either. Without writing a mini essay, the best thing you can do to mitigate any and all future problems is to buy your own proper router which will manage your network for you and work independently from the shub and put the shub in modem mode and use it solely as a modem. If the shub goes down for whatever reason your lan stays up and all your devices remain connected to one another. The reason why your lan is dropping (not that it should) is because whatever is causing the shub is crash. You are assuming that it is an internet connection problem but it is more than likely a general fault with the shub which is manifesting itself by firstly dropping the wan connection (port 1) and quickly dropping the other lan ports and/or causing the router part of the shub to crash. The next time it happens the best thing you can try and do is to connect to the gui on 192.168.0.1 and see if you have still got connectivity to the shub. It probably isn't so much that the devices can't talk to one another, it is probably the shub has crashed and each device has dropped their connection to the shub and aren't connected to the network which is why they can't talk to one another.