Game Lags when 2 same Objects in scene

The topics says for it self. When I put 2 exactly same object/prefabs in the one scene, either game is playing or in edit mode, the whole FPS drops like to 20.

I disabled shading modes in my objects, But ofc when I enable them the objects look ugly shaded.
I set this settings:

In Model settings > Normals & Tanglements:

Normals: Calculated
Tanglements: None

This will disable that ugly smoothing in game and the objects looks nice and normal. Why I set normals to import and tanglements to Calculate, the whole scene/game laggs as described above.

Pls where is the problem.

would need to use unity pro debugger as the easiest means of tracking down the issue (is it memory is it a funciton freaking out, who knows ) Use the debugger thats what it’s there for.

(don’t have it? do the 30 day trial)