After 24 hours Firebase stops working but if I update pods it starts working again

I am working on Firebase and I have one query. I have login through Firebase and have fired insert, update, delete queries.

Here is my code:

[self.data observeEventType:FIRDataEventTypeChildAdded withBlock:^(FIRDataSnapshot * _Nonnull snapshot) {
        NSArray *array = snapshot.value;
        NSLog(@"%@",array);
    }];

This block works perfectly but after every 24 hours it stops calling. However, if I update pod then again it starts working.