I understand how confusing this problem can be for you, especially since this is not easily identified. The insulation inside the dishwasher door is made of foam. In order for the water to get into the door to damage that foam, there would need to be a hole or damage to the door. It is more likely that these chunks are coming from the door seal. Your dishwasher has a rubber gasket piece that fits on the inside perimeter of the door. While your dishwasher is running, water collects in the bottom of the tub and is sprayed throughout the dishwasher. The door gasket keeps the water from leaking out between the door and the front of the dishwasher. Since the gasket is made of rubber, it eventually wears out from age and exposure to heat from the dishwasher’s heating element. If you find that the gasket is brittle, cracking or otherwise damaged, peel it off and apply a fresh gasket, which you can purchase from an appliance service center.
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