VariableListener corruption: Impossible VariableListener corruption(-1hard)…but all shadow variables is the same …

Describe the bug
I think I set the variable listener trigger order correctly, and defined a seemly correct constraint.but it told me I have a variable listener corruption.

To Reproduce

This is my Assign class
@PlanningEntity
public class Assign extends AbstractPersistable{

    @PlanningVariable(valueRangeProviderRefs = "customerList",nullable = true)
    protected Customer customer;

    @PlanningVariable(valueRangeProviderRefs = "serverStationList",nullable = true)
    protected ServerStation station;

    @PlanningVariable(valueRangeProviderRefs = "demandChoices",nullable = true)
    protected Long assignedDemand;

    ...
}
----------------------------
This is my Customer class
@PlanningEntity
@Setter
@Getter
@AllArgsConstructor
@NoArgsConstructor
@ToString
public class Customer extends AbstractPersistable{
    
    protected long maxDemand;
    protected Location location;

    /**
     * 需求等级，对应服务站可服务等级。没确定上限，按越高越好
     */
    protected int demandLevel;

    @InverseRelationShadowVariable(sourceVariableName = "customer")
    @Schema(hidden = true)
    protected List<Assign> assignedStations=new ArrayList<>();

    @ShadowVariable(sourceEntityClass = Customer.class,sourceVariableName = "assignedStations",variableListenerClass = RemainingDemandListener.class)
    // @Schema(hidden = true)
    protected Long remainingDemand;

    …
}

There is also a ServerStation class (Omitted)

Now this is key parts in my RemainingDemandListener.class
@Override
    public void afterVariableChanged(ScoreDirector<FacilityLocationSolution> scoreDirector, Customer customer) {
        updateRemainingDemand(scoreDirector, customer);
    }

    private void updateRemainingDemand(ScoreDirector<FacilityLocationSolution> scoreDirector, Customer customer){
        // if(customer==null){
        //     return;
        // }
        
        long remainingDemand=customer.getMaxDemand();
        for (Assign assign : customer.getAssignedStations()) {
            if(assign.getStation()!=null && assign.getAssignedDemand()!=null){
                remainingDemand-=assign.getAssignedDemand();
            }
        }
        remainingDemand=remainingDemand<0?0:remainingDemand;
        scoreDirector.beforeVariableChanged(customer, "remainingDemand");
        customer.setRemainingDemand(remainingDemand);
        scoreDirector.afterVariableChanged(customer, "remainingDemand");
        
    }

Finally, my constraints about this variable:
Constraint noRestDemand(ConstraintFactory constraintFactory) {
        return constraintFactory.forEach(Customer.class)
                .filter(c->c.getRemainingDemand()!=0)
                .penalizeConfigurable()
                .asConstraint(FacilityLocationConstraintConfig.NO_REST_DEMAND);
    }

Environment

timefold 1.3:

Output of java -version:17

Output of uname -a or ver:

Additional information

Provide any and all other information which might be relevant to the issue.

Start by reproducing the corruption with the provided Assign and Customer planning entities and the RemainingDemandListener implementation. Inspect the shadow-variable declaration, listener trigger order, and the before/after notifications around remainingDemand, then compare the reproduced failure with the reported corruption message. Done means the supplied model no longer reports variable-listener corruption, or the issue has a documented minimal cause and reproduction.