It may take a few minutes for the washing machine to cool down and for the lock to release.
Samsung washing machine door will not lock.
Child lock also will lock the door on some models like front loaders.
If the door lock is defective the washer door will not latch properly.
For front load models drain the emergency hose.
If the door remains locked when the cycle is finished push start pause to clear the lock.
The door lock can fail either mechanically or electrically.
Normally waiting for the cycle to end is all you need to do to unlock the door or turn your washer on if it s off.
Once the water is gone the door will unlock.
Your washer door locks to prevent water from coming out especially for front load models.
Inspect the door lock for damage.
This last week it stopped working.
Front load models will lock the door while water is detected inside the washer to prevent it from spilling onto your floor.
If your samsung front load washer door does not open after a wash cycle completes and no water is inside the tub you may have a faulty door lock assembly bad wiring to and from the door lock assembly a cracked or loose door door lock assembly that causes the washer door to not operate properly a faulty control board bent washer door hinges or faulty control board wiring.
Also found this on the samsung site for your issue as i expect you know the child lock is not on they seem to think people are daft.
After pressing the start button there is the common starting noise like the drain pump followed by the lock of the door.
Normally waiting for the cycle to end is all you need to do to unlock the door or turn your washer on if it s off.
Child lock also will lock the door on some models like front loaders.
If you get stuck though you can drain the water from front load washers using the emergency drain hose.
Once the washer door is closed the washer can begin operating.
The door lock secures the washer door shut during operation.
The display turns on like normal and selecting the type of cycle works fine.