OK, so here are a few points to consider.
If they "updated firmware" that could mean 2 things, they updated to a new revision of the General release (A version numbered 100.XXX.057.0960X) that doesn't have many of the fixes available in the Spar releases (currently it would be version 100.XXX.018.01610) which is a vastly better release in every way, but is not available via the drivers page on Xerox.com (You have to dig through the Xerox.com/security site)
Grab that and install it from here if they installed the General.
Then we have the Power saver itself, if it was set by someone to be Sleep and wake at scheduled times then what you are seeing is expected, it definitely is not the default setting though, someone would need to have applied it
Check/change it here:(1)
EWS > Properties > General Setup > Energy Saver
Also take note of the (2) option listed there on the same screen in the above screenshot, there is an odd thing on these devices where the USB port, when not set to powered, will actually clock down the NIC to save power too, so it will go from Gigabit, to 100 Full, to 100 Half et al, until a job comes in, and in some (read many) environments it will actually cause a temporary disconnnect during the switch, which can cause the driver port to time out the job, and the machine won't wake.
In short, set the USB mode to powered and update the firmware if on anything but the latest I linked, I'm pretty sure the USB thing is your issue.