Two issues.
the first is a retricted drain . either the hose is kinked or a blockage at the drain valve, or where the hose joins the sink plumbing. disconnect it from the plumbing and let it run into a bucket to observe the flow.
The second is, the float protecting an over fill is not shutting off power to the fill solenoids in the event of over filling. Try raising the front feet and keeping the rear as low as possible to bias the water to the rear of the tank.