My dishwasher stopped draining. It is not clogged. I ran a cycle while watching, and the drain solenoid engaged but didn’t drain. As I watched I saw that the white plastic piece was not all the way down (barely) I pushed it down the rest of the way and the drain did it’s thing.

Is this typical of old drain solenoids?

Does it seem that replacing the solenoid and plastic arm will fix this?
Thanks