So you think it's not the gear position switch why?
Yes, I'm sure you are much smarter than all the dealers and tuners in the world. In fact, why would you take a 2021 back to a dealer to solve an issue that should be under warranty? Oh yeah, that's right, ask strangers on the internet and then argue with them. Makes much more sense.
Replace or investigate a small sensor? You know, the one that directly causes all your issues AND the codes specifically tell you is the issue? NAH, let's "recalibrate the ECU" or something. Because people never do sprocket changes. You're the FIRST ONE EVER! And apparently as soon as you change the gear ratio (which thousands of riders do every day) you need a new ECU! That makes tons of sense.
Why don't you keep posting the same question again and again and again on different forums until someone gives you an answer you want to hear. Keep ignoring the logical answers. Must be nice to know more than the ECU, Dealers, and Tuners.
Welcome to the ignore list.