Firebase Set Value Putting Wrong Key On Released App

I have a usermodel class with different fields. Firebase has a set value method where we can pass the object and it will automatically store the value of the object with respective usermodel's items name as a key of node. My app is working fine on debug app. But when i try to set value using the release app it saves the data but the key name is not same it is c,d,i etc.

I am initilizing the model

userModel = new UserModel(mUser.getDisplayName(), mUser.getPhotoUrl().toString(), inputUname, url, 
ratings, questions, instanceIdResult.getToken(), noti_settings);

my model class

 public class UserModel implements Serializable {
 private String uName,uDp,userName,profileLink;
 private ArrayList<RatingModel> ratings;
 private ArrayList<QuestionModel> questions;
 private String token;
 private NotificationModel noti_settings;

 public UserModel(String uName, String uDp, String userName) {
    this.uName = uName;
    this.uDp = uDp;
    this.userName = userName;
 }

 public UserModel(String uName, String uDp, String userName, String profileLink, 
 ArrayList<RatingModel> ratings, ArrayList<QuestionModel> questions, String token) {
    this.uName = uName;
    this.uDp = uDp;
    this.userName = userName;
    this.profileLink = profileLink;
    this.ratings = ratings;
    this.questions = questions;
    this.token = token;
 }

 public UserModel(String uName, String uDp, String userName, String profileLink, 
 ArrayList<RatingModel> ratings, ArrayList<QuestionModel> questions, String token, NotificationModel 
 noti_settings) {
    this.uName = uName;
    this.uDp = uDp;
    this.userName = userName;
    this.profileLink = profileLink;
    this.ratings = ratings;
    this.questions = questions;
    this.token = token;
    this.noti_settings = noti_settings;
 }

 public NotificationModel getNoti_settings() {
    return noti_settings;
 }

 public void setNoti_settings(NotificationModel noti_settings) {
    this.noti_settings = noti_settings;
 }

 public String getToken() {
    return token;
 }

 public void setToken(String token) {
    this.token = token;
 }

 public ArrayList<QuestionModel> getQuestions() {
    return questions;
 }

 public void setQuestions(ArrayList<QuestionModel> questions) {
    this.questions = questions;
 }

 public ArrayList<RatingModel> getRatings() {
    return ratings;
 }

 public void setRatings(ArrayList<RatingModel> ratings) {
    this.ratings = ratings;
 }

 public String getProfileLink() {
    return profileLink;
 }

 public void setProfileLink(String profileLink) {
    this.profileLink = profileLink;
 }

 public String getuName() {
    return uName;
 }

 public void setuName(String uName) {
    this.uName = uName;
 }

 public String getuDp() {
    return uDp;
 }

 public void setuDp(String uDp) {
    this.uDp = uDp;
 }

 public String getUserName() {
    return userName;
 }

 public void setUserName(String userName) {
    this.userName = userName;
 }


 }

Setting value from released app

Setting value from debug app