searching valid metric is better than re-train valid metric in autoFIS?

Thank you for your excellent codes. I run your autoFIS codes (autoDeepFM), but found that the valid metric after searching (auc=0.7896248002165958) is better than the retrain valid metric (auc=0.7851094769386633) in the log. i.e. [searching valid metric] > [re-train valid metric] > [official valid metric], it looks like the performance improvement is achieved by BN but autofis damages the valid metric. Something wrong ?

the valid metric after searching: the valid metric after re-train: