Android Google Vision API TextRecognizer isOperational always returns false on some devices

Question

I want to try one of google vision api on android. I added this line in gradle file

compile 'com.google.android.gms:play-services-vision:11.0.4'

also in manifest file I added this

 <meta-data
            android:name="com.google.android.gms.vision.DEPENDENCIES"
            android:value="ocr" />

And here's the code snippet

TextRecognizer textRecognizer = new TextRecognizer.Builder(this).build();
        try {
            if (!textRecognizer.isOperational()) {
                new AlertDialog.
                        Builder(this).
                        setMessage("Text recognizer could not be set up on your device").show();
                return;
            }
}

So here textRecognizer.isOperational() always returns false. I looked to other questions and found nothing that helped me. (Device storage left 4 gb, so it's not storage issue). What I'm missing? UPDATE: I'm using LG G Flex 2 And tested same code on Samsung J7 (2017) and it works perfectly. So why G FLex2 fails?