Why does the "Checker Texture" node produce flicker with "Texture Coordinates Object"? What you see is a simple plan with no double faces, checked and I'm sure.



This happens only when the mesh is at the local coordinate Z-0 height, if I move the mesh in edit mode, the flicker disappears



I'd just like to know if I'm wrong, or there is a problem.
This with the "Brick texture" node does not happen, for example.

I'm using Blender 2.83 but it seems that even with 2.82 the problem is the same
That's simply because your plane is between 2 checkers.
The checker texture is a 3D texture which alternates also in the Z axis. If you go in edit mode and move your plane up and down you will see that.
You can also rotate it to get different patterns.

In "Generated" coordinates your plane is in the vertical middle of a checker. That's why there's no artifact there.