saving data using RxDataStore<Preferences> not working using java android

I want to save data using DataStore, here is my implementation:

android {
    namespace 'com.Test'
    compileSdk 33
    useLibrary 'org.apache.http.legacy'

    defaultConfig {
        applicationId "com.Test"
        minSdk 24
        targetSdk 33
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
dependencies {
    //DataStore instead of SharedPreferences
    implementation "androidx.datastore:datastore-preferences:1.0.0"
    //RxJava2 support
    implementation "androidx.datastore:datastore-preferences-rxjava2:1.0.0"
}

This is the class I used to read and write to DataStore:

public class DataStoreUtiles {
    private RxDataStore<Preferences> dataStoreValue=null;
    private Preferences pref_error = new Preferences() {
        @Nullable
        @Override
        public <T> T get(@NonNull Key<T> key) {
            return null;
        }

        @Override
        public <T> boolean contains(@NonNull Key<T> key) {
            return false;
        }

        @NonNull
        @Override
        public Map<Key<?>, Object> asMap() {
            return null;
        }
    };
    
    public DataStoreUtiles(Context c){
        dataStoreValue = new RxPreferenceDataStoreBuilder(c,"MySettings").build();
    }

    public String GetServerStatus(){
        try {
            Preferences.Key<String> ServerStatusKey = PreferencesKeys.stringKey("ServerStatus");
            Flowable<String> Status =
                    dataStoreValue.data().map(prefs -> prefs.get(ServerStatusKey)).onErrorReturnItem("None");
            return   Status.blockingFirst();
        }catch (Exception ex){
            return "Error:"+ex.getMessage();
        }
    }

    public String SetServerStatus(String Status){
        try {
            Single<Preferences> updateResult =  dataStoreValue.updateDataAsync(prefsIn -> {
                MutablePreferences mutablePreferences = prefsIn.toMutablePreferences();
                Preferences.Key<String> ServerStatusKey = PreferencesKeys.stringKey("ServerStatus");

                mutablePreferences.set(ServerStatusKey,Status);
                return Single.just(mutablePreferences);
            }).onErrorReturnItem(pref_error);

            if(updateResult.blockingGet() == pref_error){
                return "Error";
            }
            
            return "1";
        }catch (Exception ex){
            return ex.getMessage();
        }
    }
}

and I call the class in MainActivity:

private CheckBox StartStopServer;
private DataStoreUtiles DataStore = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
    try {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        DataStore = new DataStoreUtiles(this);
        StartStopServer = (CheckBox) findViewById(R.id.CHBox_StartStopServer);
        String ServerStatus=DataStore.GeteServerStatus();
        if(ServerStatus == "1"){
            StartStopServer.setChecked(true);
        }else if(ServerStatus == "-1"){
            StartStopServer.setChecked(false);
        }else{
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setMessage("No Setting was saved.");
            final AlertDialog alert = builder.create();
            alert.show();
        }
        
        StartStopServer.setOnCheckedChangeListener((compoundButton, isChecked) -> {
            if (isChecked) {
                DataStore.SetServerStatus("1");

            } else {
                DataStore.SetServerStatus("-1");
            }
        });
    }
}

I tested the application on Noxplayer, when I opened the application and checked the checkbox the data is saved. But when I close and open the application again, no data was saved.

I want to create DataStore if it doesn't exist

dataStoreValue = new RxPreferenceDataStoreBuilder(c,"MySettings").build();

Does this line create a Datastore every time I call it or open it if exist and create it if not exist? please provide me solution in java.