ParseObject.pinInBackground doesn't work when the object contains a ParseFile

Question

I'm trying to fix this issue for like past 12 hours.

I've finally narrowed down the problem to - When I use the following code, I'm not able to pin the object. When I run the query later, it returns zero results.

ParseFile file = new ParseFile("image.png", byteArray);
file.saveInBackground();
chatObject.put("picture", file);

But, when I don't add ParseFile to the chatObject, I'm very well able to pin the object and query it later.

The following is the way I'm pinning the object -

chatObject.pinInBackground("unsent", new SaveCallback() {
            @Override
            public void done(ParseException e) {
                if (e != null) {
                    e.printStackTrace();
                }
            }
        });

I'm pretty sure my code is correct. Anybody knows how to fix this ?