Counter on EventValueListener doesn't count for counting the number of the database

Question

I want to set value of counter to every post user made and it saved to database. so in recycler view i can PostRef.orderByChild("counter");

User 1 post then set value start of counter 0 then other user or the same user posted

The value of the counter should be 1 then 2, 3, 4, 5 etc (it should count with getChildrenCount(); but it doesn't work, why? it shows number 9

I also put StoringPostToFirebaseStorage(); under the countPosts = dataSnapshot.getChildrenCount(); line at it works for counting 1, 2, 3 but it also updates the old post to the same number as the new one that was just posted.

Am I coding it wrong?

PostsRef:

PostsRef = FirebaseDatabase.getInstance().getReference().child("posts");

the counter:

private void CounterPosts() {
  PostsRef.addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
      if (dataSnapshot.exists()) {
        countPosts = dataSnapshot.getChildrenCount();


      } else {
        countPosts = 0;
      }
      StoringPostToFirebaseStorage();
    }
    @Override
    public void onCancelled(@NonNull DatabaseError databaseError) {

    }
  });
}

the StoringPostToFirebaseStorage();

private void StoringPostToFirebaseStorage() {
  LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
  Location location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
  longitudesave = location.getLongitude();
  latitudesave = location.getLatitude();

  //edit test 1 HashMap<String, Object> postsMap = new HashMap<>();
  HashMap postsMap = new HashMap();
  postsMap.put("uid", current_user_id);
  postsMap.put("posttext", PostIntiText);
  postsMap.put("date", saveCurrentDateForUser);
  postsMap.put("time", saveCurrentTimeForUser);
  postsMap.put("postimage", downloadImageUrl);
  postsMap.put("longitude", longitudesave);
  postsMap.put("latitude", latitudesave);
  postsMap.put("district", district);
  postsMap.put("city", city);
  postsMap.put("counter", countPosts);
  PostsRef.child(current_user_id + postRandomKey).updateChildren(postsMap)
    .addOnCompleteListener(new OnCompleteListener < Void > () {
      @Override
      public void onComplete(@NonNull Task < Void > task) {
        if (task.isSuccessful()) {
          SendUserToMainActivity();
          Toast.makeText(PostActivity.this, "Posted successfully", Toast.LENGTH_SHORT).show();
          loadingBar.dismiss();
        } else {
          String errormessage = task.getException().toString();
          Toast.makeText(PostActivity.this, "Error:" + errormessage, Toast.LENGTH_SHORT).show();
          loadingBar.dismiss();
        }
      }
    });
}

The Database Image