Even late PP mags for guns that both feature the left side magazine release button won't interchange.
Many if not most early .380 acp PP guns had a bottom, heel mounted, magazine releases while the .32 and smaller caliber guns had the side release button.
Walther had a lot of trouble trying to make the side mount latch work on the .380 guns.
The snappy, sharp recoil would cause the shooter to inadvertantly hit the side mount magazine release or the catch just plain couldn't hold the heavier, loaded .380 magazines in place.
Manurhin of France finally perfected a successful side mount catch for the .380 caliber guns Post-War.