I'm confused. All maps show this residential area is in 78048, even though street registers (e.g. https://onlinestreet.de/strassen/Ursula-Haider-Stra%C3%9Fe.Villingen-Schwenningen.908392.html or the one you linked) say this street and the ones that connect with it are in 78052.
I'm unsure what is correct.