Question about Samsung WW90CGC04AAEWS

You can add more laundry after the washing machine has started by pressing the Start/Pause button to pause the cycle, then opening the door to add items, and pressing Start/Pause again to resume. However, this is only possible if the water level is not above the door seal and the cycle is not too far advanced. If water has filled past the rubber seal or the wash is well underway, the door will remain locked for safety and you cannot add laundry.