Ambiguous route error in Vaadin 14 web application running on Tomcat

Question

I am getting the following error when I deploy a Vaadin 14 web application on Tomcat 9.0.46

 Caused by: com.vaadin.flow.server.AmbiguousRouteConfigurationException: Navigation targets must have unique routes, found navigation targets 'xx.SForceFindPaymentView' and 'xx.SForceFindPaymentView' with parameter have the same route.

The class is defined as follows:

@Route(value = "sf-find-payment", layout = MainLayout.class)
@PageTitle("Find Payment")
public class SForceFindPaymentView extends FindPaymentView implements HasUrlParameter<String>, IAAPConnection {

And the parent class is defined as follows:

@PageTitle("Find Payment")
@Route(value = "find-payment", layout = MainLayout.class)
public class FindPaymentView extends VerticalLayout implements HasUrlParameter<String>, IAAPConnection {

The only difference between the parent class and the derived class is the way the parameters are handled in the setParameter() method.

The setParameter method has the following signature

 @Override
 public void setParameter(final BeforeEvent event, @OptionalParameter final String parameter) {

The odd thing is if I delete the war and redeploy the exact same war file the problem goes away and the application installs successfully.

I tried removing the @OptionalParameter annotation but that made no difference. The error message seems to see two routes for the same class, one with a parameter and one without so I thought if I removed the @OptionalParameter in both the parent and derived class, that might help but it made no difference.

Grateful for any suggestions.