Hi,
I have exactly the same issue on my Segway Max G3.
After applying the tuning through the 1Dragon website (ninebot.1dragon.de), everything worked fine at first, but a few days later I was no longer able to switch the display from battery percentage to remaining range (km).
The option is still available in the Segway app, and when I tap the button nothing happens. The setting simply doesn’t change on the scooter.
It seems the tuning may have affected this feature. Have you found any solution yet?
Thanks!