Chinese manufacturers don't seem to be very interested in after sale repairs. They would prefer you buy a new bike rather than fix the one you already have. Even if the controller is the same as last years model, all the plugs might be different. That complicates repairs, and is one of the main reasons shops don't like to offer repairs to brands they don't sell.
It's not just the Chinese either, increasingly it's the same with dishwashers, washing machines, window air conditioners, televisions, ........
It's not just the Chinese either, increasingly it's the same with dishwashers, washing machines, window air conditioners, televisions, ........