Help with Follow path

[catcat]

I’ve been trying to figure out how “follow path” works.
If I create a bezier circle and place a cube exactly on the path, then enable follow path for the cu9be, the cube shifts what looks like the length of the radius of the circle.

The same thing happens with an armature. I get weird results as objects or armatures that I was to have follow a path shift all over the place.

What am I doing wrong?

[LazyVirus]

@catcat

If I create a bezier circle and place a cube exactly on the path, then enable follow path for the cu9be, the cube shifts what looks like the length of the radius of the circle.

It happens when the origin of the circle is in one of its control points.
Select the circle → Shift+ALT+Ctrl+C → Origin to geometry.