Thanks for following up to let the community know how you resolved this. When I setup a new Fiery driven printer I always encourage people to obtain drivers from efi.com and not via WebTools. That's not so important on Windows but it's very often important on MacOS, as you discovered.
Some of our staff running Catalina on Macs are getting the error "Filter failed" when trying to print to our Versant 180 printer. Not sure what has changed lately but I have multiple people inform me of this. At one point, they were able to print with no issues. Any thoughts/suggestions? Looking forward to hearing back from you.