All of my prefabs are rotated on x by 90?

Questions & Answers
1

I created my characters in my game using prefabs.
Everything was fine, but recently, Unity started rotating all my prefabs on x by 90.

No matter what I do, they all revert to 90.
I have dragged them into the world, where you can see the incorrect rotation.
I fix the x rotation manually, and everything seems fine.
I apply the modification to the prefab and the values seem to update
Once I select a different prefab and return to the modified one, it is once again rotated by 90 on x.

I have now modified my code to compensate, but it seems so unnecessary.
(I rotate the characters upon initiation now to compensate for the 90 degree rotation)

How can I find out why my prefabs started rotating around x?

2

Ironically, I’m not even touching a 3D tool yet.

My capsule objects that was created in Unity itsself are rotated by 90 degrees on x.

I have now experimented even further:

  1. Objects imported from Maya have the same behaviour
  2. Objects imported from Blender have the same behaviour
  3. Objects created in Unity has the same behaviour

As long as I don’t convert an item to a prefab, it stays correctly oriented, but the moment I make it a prefab, its x rotation goes to 90…