The sound of refrigerant flowing through the evaporator coil, some manufactures do a better job of concealing that noise than others.
A cold evaporator will collect raspatory moisture and sweat from the passengers if the system is set on “Recirc”, use fresh air to reduce odors.
I can’t speak to OP’s specific A/C configuration, but I replaced my home refrigerator w/a 2020 model, and it uses a different type of more eco-friendly refrigerant. The manual says the customer should expect considerable more noise from the fridge compared to older Freon-designs, and the manual is correct. All sorts of weird noises, hissing, gurgling, buzzing, but the fridge works perfectly, just normal sounds with that refrigerant I guess. So if sounds remain the same since purchasing car, maybe it is something like that, nothing wrong, normal, just have to live with it.