Parse findObjectsInBackground returns empty array

Question

I'm using Parse v1.17.2.

I have a PFQuery which should return objects from remote in Background.

//* ObjC *
PFQuery *custQuery = [CustomSentences query];
[custQuery fromLocalDatastore];
[custQuery whereKey:[CustomSentences userRef] equalTo:[PFUser currentUser]];
[custQuery whereKey:[CustomSentences visibility] equalTo:[NSNumber numberWithBool:YES]];
[custQuery orderByDescending:[CustomSentences updatedAt]];
[custQuery findObjectsInBackgroundWithBlock:^(NSArray *localObjects, NSError *error){
    localObjects = [ParseUtils removeInvalidObjects:localObjects];
    cust(localObjects,error);
    PFQuery *custRQuery = [CustomSentences query];
    [custRQuery whereKey:[CustomSentences userRef] equalTo:[PFUser currentUser]];
    [custRQuery findObjectsInBackgroundWithBlock:^(NSArray *remoteObjects, NSError *error){
        remoteObjects = [ParseUtils removeInvalidObjects:remoteObjects];
        NSLog(@"Local Object Count : %lu ; Remote Object Count : %lu",(unsigned long)[localObjects count],[remoteObjects count]);
    }];
}];

The remote objects array is always empty. Please help. How do I debug it..