Loss function range normalization
I agree with the referee. When your loss is composed from different terms, you should add a mechanism that enable you to adjust the contribution off those terms.
Just create a new hyperparameter (usually called lambda) and use it like that:
$L = L_1 + \lambda L_2$
You have to find the right lambda with cross-validation.
This is used in most of the papers.
For example : https://arxiv.org/pdf/1806.08462v1.pdf page 3