Glitch/overlapping when two objects are on exactly same transform

Is this just a shader problem or something else?

Greetings fellow devs.

I've been struggling with this same problem occasionally when I started using unity.

My current project is using a prefab maze parts (just like in the
Labyrinth board game) and they're instantiated to their certain places
when player presses keyboard button. Works like it should. :)

But when two prefabs (using box colliders,mesh,kinetic rigidbody and
standard shader) are placed to scene problem occurs with some prefabs ->
When two prefabs end to same coordinate they start clipping.
Added a gif to show what i'm typing about.

Gif of my problem in imgurl

This is only happening in play mode. In editor window everything looks good. :P
Problem can be "fixed" by adding -/+0.001 to one of gameobjects current
scale and glitch is gone. But! then there's a small visible edge and i'm
trying to have smooth surface all around the maze.

So is this easily prevented by changing some player settings, setting
custom shaders to prefabs/gameobjects or do I need to micro adjust
and checking every one of them in play mode just like i've been doing to this day?

And here's pic one of prefabs just for kicks:

Picture of one of Prefabs