sonarQube - make field transient or serializable

I'm trying to solve the following violation reported by sonarQube plugin for Jenkins: "make 'update' transient or serializable.". Gravity: critical, tag: serialization.

I have the following shared interface

public interface MPUpdate {

    void apply( SoapService svc, byte[] jerseyClientResp ) throws MPException ;
}

The following enum is the entry point for the application logic

public enum DomainResource implements MPUpdate {

    PROGRAMMES( new ProgrammeUpdate() ),
    PRODUCTIONS( new ProductionUpdate() );
    // more enums

    private DomainResource( MPUpdate update ) {
        this.update = update;
    }

    private final MPUpdate update; // Sonar: make "update" transient or serializable, priority: critical, tag: serialization

    @Override
    public void apply( SoapService svc, byte[] jerseyClientResp ) throws MPException {
        update.apply( svc, jerseyClientResp );      
    }
}

One of the unit of logic initialized through the enum

public class ProgrammeUpdate implements MPUpdate {

    private final ResponseConverter<ProgrammeDto> responseConverter = new ResponseConverter<>( ProgrammeDto.class );

    @Override
    public void apply( SoapService svc, byte[] jerseyClientResp ) throws MPException {

        // APPLICATION LOGIC
    }

}

And finally this is how it's used:

...
String levelFromUrl = getLevel(); // eg. "programmes"
MPUpdate resource;
resource = DomainResource.valueOf( levelFromUrl.toUpperCase() ); 
...
resource.apply( soapService, jerseyClientOutcome );
...

Any help? Does the use of enum improve performance for logging?

Many thanks