I got such a bug, what can it be and how to fix it?
We need more information…with just a cylinder with an array modifier as you show…there is no reason that would cause this in Blender…but if you look at your screen-shot your gizmo is also all smeared like the edges…so it leads me to think it is a Grafix card problem where you moved around the scene and the edges rendered as it moved.
- Update your graphics card drivers. If that isn’t an option,
- Get a new graphics card. If that isn’t an option,
- Get a new computer. If that isn’t an option,
- Revert back to an earlier version of Blender that has less updated graphics card requirements.