I can't hide the Loading indicator View

if (email.isEmpty()) {

        showProgress(); // I defined this function using AVLoadingIndicatorView in BaseActivity

        auth.signInWithEmailAndPassword(email, password)
                .addOnCompleteListener(getActivity(), task -> {

                    hideProgress(); // hide the AVLoadingIndicatorView

                    if (task.isSuccessful()) {
                        // Sign in success, update UI with the signed-in user's information
                        moveToSubjectSelectFragment();
                    } else {
                        Log.w(TAG, "createUserWithEmail:failure", task.getException());
                        Toast.makeText(getActivity(), "Login fail", Toast.LENGTH_SHORT).show();
                    }

            });
}

public void showProgress() {
    runOnUiThread(new Runnable() {
        @Override
        public void run() {
            if(activityIndicator != null) activityIndicator.show();
        }
    });
}

public void HideProgress() {
    runOnUiThread(new Runnable() {
        @Override
        public void run() {
            if(activityIndicator != null) activityIndicator.hide();
        }
    });
}