Hi Unity’s,
we are Katrin & Mathias from germany, we are both somewhat older but creative people, both we are unfortunately pensioners since covid-19.
So we thought we could develope a computer-game, just of our own ideas! And with Unity we found a great Tool for that with a great comunity behind.
We both watched a loooot of learning tutorials to let our dream of an own game come true, but we still get stuck on Unity’s Prefab-System 
Okay, we understand: a Prefab could be easily used more than once. It also can be Instanced by the GPU which impacts the game-performance. Right?
Also, like the tutorials say, a modification on the prefab-base will affect all instances in scenes directly too.
But: this is not the case?! Modification an (unpacked) Prefab in his Folder does (for us) NOT affect all game-
objects spread on our scenes based on that unpacked Prefab. Why??
And our biggest problem is: we cant change size/rotation/and so on, on Prefabs, even not if we unpack em! Why? How can we simple rotate Prefabs?
Cheers,
K&M