Repro step (in 5.4.0b1)
- create a game object with an horizontal translation animation
- create a child game object with a vertical translation animation
- move the cursor somewhere in the middle of the animation
- in hierarchy, duplicate the child game object

The duplicated child game object has a curve, which is neither constant nor a duplicate of the original.

Not a regression - it's always been that way. As discussed with team, now entering it as a bug.