the flood is on front area only right? in this case most probably it is due to water leakage from water shield plastic, it cannot hold too much water inside door
during heavy rain or even on light rain if u park ur car on slope (front facing downward) water cannot be drain out from inside door, the water drain on neo door is small and placed in the middle so if the amount of water going in is more than going out, u will have water leakage,
so replace the rain shield