Why did all the gameobject meshes in my scene automatically combine to form combined mesh ?

Why did all the gameobject meshes in my scene automatically combine to form combined mesh ?

Because of this combined mesh I am unable to resize or change position of my gameobjects ?

Why would unity do this without any warning ? And there is no documentation regarding this whatsoever !!

Can someone kindly help me please ?
@KelsoMRK

That’s static batching. You can disable it in Edit → Project Settings → Player, or to disable it on particular items just untick the static checkbox in the inspector.