I had one with this issue a few months back. Thought the customer had screwed the sides of the tub into the cabinet (had it happen before) and it wasnt. Called the $ears tech line and they said there was an issue with tubs made wrong from the factory and the tub would need to be replaced. If this is a new d/w, you'll need to call whirlpool and get them to send a new tub.
There might be a service pointer, but not totally sure.
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