SMEG DC122W is continuing to fill and overflow triggering aquastop?

Our smeg dishwasher model no. DC122W is continuing to fill on each cycle until the main chamber overflows and triggers the aqua stop. When manual activating the Aqua stop the pulp drains no problems. I have dismantled all the connector hoses, drainage hose and hose between pumps / filters to check for blockage but all draining fine which makes me feel that the system is not registering when to stop filling and drainage is fine. If this is the case would replacing the water inlet valve or flow meter Potentially fix the issue? What could it be? The machine goes through drain and then fill cycle, then starts the main pump to move water round but continues to fill until it overflows the main chamber Thanks