Just because the Fiery is online does not mean that the scan service is running.
So open Webtools and see if you can see the scans there and retrieve them, but I'm thinking you won't.
Likely you will get an error about Mydocs not loading, in which case you would likely lose a lot of settings to resolve it.
The 2 methods would be to
1. Reset the Fiery, which will delete every job and customization on it, you would have to set it all back up again
2. Have the Fiery loaded by a Xerox tech, which does the same as above, but also wipes any updates or patches from the system, Xerox is not responsible for those so it would be up to you to either install them manually (Well over 100 of them) or set the machine with DNS and enable the auto updates through EFI.
Attached pdf guides through option number 1, skip webtools though, use CWS via Server > Configure and just hope Java lets you do it.