def eval(encoder, classifier, data_loader):
    ...
    # evaluate network
    for (images, labels) in data_loader:
        ...
        print(pred_cls)
        print(labels)
        print(pred_cls.eq(labels.data).cpu().sum())
        acc += pred_cls.eq(labels.data).cpu().sum()
        ...

Use this code to check your values in the validation loop.
PS: Also, please stick to one user account.