Hey Frank,
Thank you for your reply! Your reply has cleared some aspects. Furthermore, reading through your thread it helped me even more.
However, I am very new to machine learning, and I am slightly confused with the following terms:

multi-label, multi-class  classification

Would you care to explain this for me?
Furthermore, your method seems to me that what I already have done is pretty much the same? as the sigmoid function is internally performed with BCEWithLogitsloss Have I understood correctly?
Thank you!