Trees have gone mad.

Hello!

I've been playing with Unity for a few months and it has been an fun and inspiring application to in. One challenge has me pulling my hair out and I have no clue why it is occurring. I'm hoping someone may be able to assist!

1. I've created a terrain and I'm manually placing prefab trees on the terrain.
2. Sometimes when I move or position one of the trees, all of the prefabs of this tree rotate randomly at once.
3. All of these trees are now broken and must be repositioned.

This kills my soul, as it is needless rework.

I've tried to solve this a few ways. One is back-ups of the project. When I write down all of the tree values of this prefabs and reenter them into the current project they don't match up at all. So it sounds like the prefab is being altered, right?

Yet, the prefab in this still has the same rotation, position, and scale settings (0,0,1) as the old. But when this prefab is dragged into the scene it is now horizontal. So, it is being changed.

Gah! I have no clue what I'm doing wrong. Really appreciate any feedback so I can focus on not rebuilding things.

Thank you for your time.