It's been one year since the last update for original mi box 3 international, no security patches no android update, no kernel update, no bug fixes NOTHING
while it has the exact same hardware as the new mi box
there is no reason to not updating the old model when it has the same hardware
They updated the box from Android 6 to Android 8 that's already better then 95% of the boxes that never get any Android update at all.