I’m applying transfer learning to the resnet50 from torchvision models, i.e. replaced the last fc layer with 2 neurons for binary classification problem. All other layers are frozen. I started training the network with learning rate 1e-2 and reducing it by a factor of 0.1 after 5 epochs if validation loss is not decreased. However, when the learning rate decreases from 1e-2 to 1e-3 for the first time, there is a suddent and very big increase in training accuracy (therefore decrease in the loss). Training accuracy jumps from around 54% to 96%. I attach the loss and accuracy plots. I use cross entropy loss. What might be the reason of this sudden big increase in the training accuracy?