I have three FS850 scanners and intermittenly after an update one or more will go offline and will need to be physically power cycled.
I am running 6.8 and I just had another do it, this morning after an OS Prints update.
I am having it rebooted right now, and will open a ticket with support, but I was wondering if anyone has seen this before and if a solution exists.
Under Manage Engines> Preferences>Network Options there is a Network Connectivity Detection option. If you are using this I'd disable it and see if the issue goes away.