I can do the box in about 2/3 of the allowed test space on my DR-Z, but when I used to ride my GSX-R on the street, I sometimes struggled to stay inside the lines at all. It took me months of weekly practice to finally get the box down on that bike. The combination of very high gearing in 1st gear (it’s geared for 82mph), almost no handlebar turning range lock-to-lock (a safety feature for high-speed head shake), and the combination of extreme top-heaviness and almost no fork rake made it extremely difficult to turn tightly at low speed. A tiny bit too little throttle/clutch, or a bit too much pressure on the bars and the bike would just dive into a lean. I could turn in a really tight circle, but only after slowly tightening it up from a bigger circle. That first dive from upright to full lean was just terrifying. Just keep practicing and, even though you’ll always find it easier on other bikes, you’ll eventually get it. Be stubborn