Detectron2- How to log validation loss during training?

I copied the idea from mnslarcher and wrote the following two functions for my keypoint detector (resnet50 backbone) algorithm.

def build_valid_loader(cfg):
    _cfg = cfg.clone()
    _cfg.defrost()  # make this cfg mutable.
    _cfg.DATASETS.TRAIN = cfg.DATASETS.TEST
    return build_detection_train_loader(_cfg)

def store_valid_loss(model, data, storage):
    training_mode = model.training
    with torch.no_grad():
        loss_dict = model(data)
        losses = sum(loss_dict.values())
        assert torch.isfinite(losses).all(), loss_dict

        loss_dict_reduced = {k: v.item()
                                for k, v in comm.reduce_dict(loss_dict).items()}
        losses_reduced = sum(loss for loss in loss_dict_reduced.values())

        if comm.is_main_process():
            storage.put_scalars(val_loss=losses_reduced, **loss_dict_reduced)
    model.train(training_mode)

then in plain_train_net.py I am calling them as bellow.

    val_data_loader = build_valid_loader(cfg)
    logger.info("Starting training from iteration {}".format(start_iter))
    with EventStorage(start_iter) as storage:
        for data, val_data, iteration in zip(data_loader, val_data_loader, range(start_iter, max_iter)):
            iteration = iteration + 1
            ..
            ..
           #At the end of the for loop.
           # Calculate and log validation loss.
            store_valid_loss(model, val_data, storage)

after 1k iteration, loss_keypoint is increasing, but total_loss is same compared to without store_valid_loss call. What am I missing? Can anyone please help to understand? I am using 4 GeForce RTX 2080 Ti.