Spring Cloud ZooKeeper Discovery Client Not Register on ZooKeeper when using SpringBootServletInitializer

I have a spring boot application that use spring-cloud-stater-zookeeper-discovery to register the service, but it doesn't work.

1. the application is deployed as a WAR.

    @SpringBootConfiguration
    @EnableAutoConfiguration
    @EnableDiscoveryClient
    public class MyApplication extends SpringBootServletInitializer {
    
        @Override
        protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
            return application.sources(MyApplication.class)
                    .properties("spring.cloud.zookeeper.discovery.instance-host=" + getHostName())
                    .web(true);
        }
    }
    

2. the application has connected to the zookeeper instance. Ping messages to zookeeper can be seen in the application's log and the output of STAT command shows a connected zookeeper client.

3. the application does not register watchers to appointed zookeeper path, i.e., /services. This can be confirmed by sending WCHC command to the zookeeper.

Spring Boot version: 1.5.9

spring-cloud-stater-zookeeper-discovery: 1.2.0.RELEASE

web container: tomcat 8.5.23

No source files or tests are named. Start by reproducing the WAR deployment with Spring Boot 1.5.9, Spring Cloud Zookeeper Discovery 1.2.0.RELEASE, and Tomcat 8.5.23, then trace discovery initialization and registration. Done means the deployed application registers its service and watchers under the configured ZooKeeper path.