Nowadays whenever I record with my Lumia 640XL video recorder, it always miss the scene between 0:20-0:23. When I play the video, it just jumps from 0:20 to 0:23.
I did not hear this problem earlier but are you recording on a SD card or on the internal memory.
If you record on a SD card could you change this to the internal memory and check if you still have the same problem.