Why we don't observe a magnetic field on the nucleus due to electron orbit?

When we study the spin-orbit interaction, we only find the electric field in the frame of the
nucleus, while in the electron referential frame, we find the magnetic field due to the relative orbit
of the nucleus around it (by the Lorentz transformations).

Why is this so? There shouldn’t be also a magnetic field in the nuclear reference system because of the electron orbit?