In aviation instruments aircraft speed is typical measure in knots per second, per the International Civil Aviation Organization. Only a few countries, Russia and China, measure velocity in meters per second. The same is true for flight levels, per ICAO it based on feet, FL290 is 29,000 feet above mean sea level (MSL) where again, Russia bases its flight levels and separation rules using meters.
Should DJI been based in Japan, I would have expected the readings to be based on knots/sec and feet AGL (Above Ground Level) rather than in meters.