Gunwalker was an attempt to track the sales of guns. The tracking technology failed, so the project was given up.
Fast and Furious - on the other hand - was in no sense an attempt to track the sales of guns. No tracking technology was used, and when one agent tried to apply his own tracking technology it was refused.
Instead: Fast and Furious was a wholesale movement of guns to Mexican criminals without any conceivable policing payoff. It was an attempt to spam blood-stained Mexico crime-scenes with US-registered weapons and so exert dishonest pressure on 2nd Amendment rights.
There has never been an operation named ‘Gunwalker.’