On Fri, 30 Nov 2018 01:36:04 -0800 (PST), StarDust
wrote:

https://www.youtube.com/watch?v=rIesWBTUeiI

It's called Geostationary Oscillation. Not all geo sats are directly above the equator, they can be slightly inclined whether by design or insertion failure. The satellite's gyros will compensate for the movement to keep the footprint centered. Sirius XM sats do a huge "figure 8" from North to South and back to ensure a uniform footprint for moving vehicles. A. Kemp - Lockheed Martin Astronautics?

By definition, all geostationary satellites are above the equator, and
do not oscillate. If they are inclined, by have a 24 hour orbit, they
are called geosynchronous, and show that north/south oscillation.

All geostationary satellites are geosynchronous, but not all
geosynchronous satellites are geostationary.