Ford Aspire 1.2 Petrol Engine RPM fluctuations Problem

Ford Figo Aspire 1.2 Petrol MT - Engine RPM fluctuation problem. Car purchased in June 2017. Facing this problem during driving vehicle in traffic / during reverse gear - whenever need to drive in half clutch situation. This Video captured at a traffic signal stop. Accelerator was at zero position. Raised this to Talera Ford Pune dealer and Ford India Technical Team. They inspected vehicle for 3 days and communicated that there is no abnormality found and failed to solve the problem saying it is normal in all 1.2 petrol Ford cars. As of date observed this problem in another 2 Ford petrol cars. Any Ford owner facing same problem? Can anyone help me to identify the possible reason for this?