I artificially changed the dataset so that all my samples correspond to label 1 i.e. for every sample, the target is [1, 0, 0, 0, …, 0]. I wanted to see whether the network was able to learn this dummy case. However, it predicts the opposite for each sample i.e. the predicted output is [0, 1, 1, 1, …, 1]. Have you observed this before?