Hoverboard?

Hello, I bought a used Robway hoverboard for my grandson, but no one could tell me what model it was.

I bought a seat for it. Now there's a small problem. If you ride it and push the two handles all the way up/down, it shuts off automatically. You then have to wait about 10 minutes before you can turn it back on, but it turns on immediately after connecting it to the charger.

I would like to know if this is intentional or if there is a technical defect.

Thank you Klaus