Hair loss on baby

Hi mommies, FTM here 🙏🏻. May I know how do we prevent bald spots at the back? 🥹 my baby is about 4 months plus now. Example of the pic as attached! There’s an old saying to cut bb hair so the hair would grow faster. 🫣 Do I really need to cut or shave my bbg hair in order for a better hair growth? Not sure if that’s a myth. #Needadvice #FTM