Fine tuning the trained model, the initial loss is quite high

Hi,

I am trying to fine-tune my previously trained model. What I did was load the model using load_state_dict and then I changed the initial learning rate to a smaller value. One thing that confused me is that the initial training loss when conducting fine-tuning is quite high, and the value is quite different from the loss I got in previous training. If they have similar model coefficients, how can they have very different losses? or if I misconducted something?

More details are given here, it is a fully connected MLP model, and the loading is as follows:

if model[tag].fineTuneSwitch == True:
                model[tag].load_state_dict(torch.load(model[tag].annModelPath))

the loss records are attached.
the previous training case (initial learning rate: 1e-3):
Screenshot from 2024-04-08 17-32-49
the fine-tuning case (initial learning rate: 4e-6):
Screenshot from 2024-04-08 17-33-02

The problem was addressed. The way of loading is right for model fine-tuning.