yes, of course sure.
Thank you so much for paying attention to my post.
the partial fc in my code was just copied from another popular opensource repository 7 for face recognition.
in fact, the major part of my code is based on this version of pytorch implementation for Arcface face recognition method. But maybe for friends who are not famillar with Arcface, they can ignore this name since it just implemented a type of loss function.
longing to find the cause of this problem with you and thanks again for your time!