To reproduce:
1. Open attached project "1025925.zip"
2. Open testing.unity scene
3. Select GameObject from the hierarchy window
4. In the inspector select couple of animation curves presets
5. Open one of the animation curves and edit them

Expected result: the curve is edited
Actual result: the curve is edited but all the curves may disappear in the inspector

Reproduced on: 5.6.5p4 2017.1.3p3 2017.2.2p3 2017.3.2f1 2018.1.0f1 2018.2.0b1

Workaround: deselecting and selecting game object again in the hierarchy window fixes the issue, but the issue can be repeated again
This might look like a minor issue, but it can impact a workflow for animation artist with lots of animation curves