I have seen the door hinges on either side get bent. Open the door and stand back and look at it, if the machine is installed level, the door should be level when open. if it slants down towards the floor, your hinges could be bent.
If they are bent, when you close the door, the door will not be in the correct position to make a tight seal.
Door hinges can bend a couple different ways, If a door spring fails, and the door flops down really hard, or from some source of weight on the door, like a child leaning on it. Also if you have custom wood panels for the front, the added weight overtime could possibly damage the door hinges. Check it out