The relevant patent infringement case Inventist, Inc. v. Ninebot, Inc. started in 2016, and the trial will not take place UNTIL 2023. https://www.courtlistener.com/docket/4411896/inventist-inc-v...
The inventor has not made any money from the invention, despite the US patent. Other links: https://www.theguardian.com/technology/2016/jan/08/hoverboar.... https://www.forbes.com/sites/wadeshepard/2018/01/31/meet-the...