Evaluate model after each epoch

[JokerSeven]

Hi, I want to ask you a question. I use train set, valid set and test set to train the model, most importantly，the date of train set and valid set that I use is totally same. But I find after each epoch, the accuracy of train set and valid set is different though I use the same data and the same model parameters. Could you tell me the reason?

[JokerSeven]