If water backs up onto your floor when the washer drains, the blockage is likely in the (the vertical pipe the drain hose slides into).

Pull the machine away from the wall. The grey accordion hose that carries water to the wall may have been crushed by the machine moving during a spin cycle.

Most front-loading and modern top-loading washers have a debris filter designed to catch coins, lint, and hair before they damage the pump. Cleaning a Washing Machine Drain Pump Filter

“Okay,” she said to the empty room. “The heart.”