I've already done that and nothing, even had the stealership look at it and they can't come up with a reason why either
Is everything stock on the scooter? Primary and final drive ratio changes can mess with the cruise. Electrical addons can mess with the serial data. And tall bars usually involve splices in the switch harnesses, which are always suspect.
Beyond that, the only way the scooter knows its in 6th is a calculation by the ecm. It basically counts rpm ticks and speed ticks then makes a comparison. If that result is within the 6th gear results window, the ecm grounds the 6th lamp to turn it on. If its enableing the cruise only when it enables the 6th lamp, it's suffering from a brain fart.
And since the cruise uses serial data, any sort of electrical add on can cause an issue by overlaying that particular signal.
Basically, pin 35 at the ecm enables the cruise, red w/green trace. After that the brakes, clutch, and bar switches can disable it via information passed back through the serial buss.
If I was going to suspect a bad buss signal on a 12, Id be looking at the clutch switch, they have a history of being wet. If the bars have been swapped out and wires spliced, then the splices to the bar switches would be suspect.
And Murphy's law says it will be a bad ecm, since that's the most expensive part.
To actually diagnose it on the shop floor would take some special tools beyond what the MoCo has. But you could do it on a dyno if you had an ecm breakout box.
At this point, pulling the main fuse is as good an idea as anything I can come up with. Wouldn't be the first time rebooting fixed a silicone malfunction.