OK, it did it before, pre-flash? it's not in the flash. I'm glad you told me that. My tune is WAY different than stock so this is not something that is in the tunes if they both did it.
Check your ground connections DO NOT THINK I'M JOKING.
I did a flash a couple weeks ago on a 2016. Guy says the bike has all the issues , hesitation, flatness, etc. Under 600 miles, wants me to flash it. I did, then when riding it had some really weird upshifts, like the gearing was to low and it rocked back and forth...very disconcerting. Never felt that before, so I worked on the clutch adjustment, throttle free play, etc. It felt fine. Guy leaves the shop, calls me in a hour, says "it's doing it again" along with some lean surge, although when he was running WOT hard accells it was fine. Now I've done almost 200 flashes, never heard anything negative like this. After think about it for a bit I told him I thought there was a bad ground connection and the coils were overheating and not producing enough energy. Sure enough, the ground on the battery was loose. I tightened it up and all the issues went away. CHECK YOUR GROUNDS!!! Steve