Unity character controller behaviour has changed since upgrading Unity

Unity has changed the behavior of the Character Controller somewhere between Unity 2017.1.1 and 2017.4.18
When changing the character controller rotation, the capsule significantly changes location in Unity 2017.4.
This did not happen under Unity 2017.1, where the capsule would remain in the same location under certain circumstances (see below).
I have created two repos in each Unity version and verified this.
It is an issue involving using the character controller with a non-zero center.


CC with no rotation


CC with modified rotation. The capsule has moved drastically.

The script is simply doing:
cc.Move(Vector3.zero), every frame.
Executing this script prevented the capsule from moving under Unity 2017.1 when altering the rotation.
This is no longer the case in Unity 2017.4.18.

I can't find anything in release notes or issue tracker regarding this.
So either
1. It wasn't working properly in Unity 2017.1.1 and Unity fixed it,
or
2. it was working as expected and then Unity broke something in the newer version of Unity.
It has to be one or the other.

So does anyone have ideas what is going on here?
Is it a new bug? Or was it already a bug in 2017.1 that was fixed?




.

 

Anyone?
The Character Controller shouldn't be behaving so drastically different without being documented somewhere.
This behavior doesn't occur in previous versions of Unity.