TM is correct. Electrons are quanta, as in quantum mechanics; so their behavior cannot be explained in simple intuitive terms like gravity and orbits.
For example, electrons don't "orbit" as you put it. If anything, they sort of pop in and out of existence around the nucleus of their parent atom. One might think of them as a cloud of electrons popping in and out of existence around the core of the atom. And the volume of space where each electron is mostly likely to be located depends on its intrinsic energy level.
But... this is important... electrons can, probabilistically speaking, actually pop into and out of the nucleus or out on the rim of our known universe. That would be a rare event for sure, but there is a finite probability of that happening for each electron.
The intrinsic rest mass energy of each electron remains fixed, but its kinetic energy (more properly its momentum) fluctuates because of the so-called quantum jitters. All quanta pop in and out of existence and according to the Heisenberg Uncertainty Principle [See source.] their energy, time, location, and velocity can only be treated probabilistically.
As a quanta, gravity has little if any effect on electrons. We know, for example, it takes the gravity of super galaxies or massive white dwarf stars to affect photons, which are also quanta. So changes in location, which are momentary at best, do not alter the potential energies due to gravity pull from the nucleus.