Reproduction steps:
1) Open attached project and proceed to "test" scene.
2) Open animation window.
3) Select object 1 (doesn't meter where hierarchy/scene view)
4) In animation window change samples value.
5) Select object 2 in scene view.
6) In animation window mouse click on a samples value (as show in the gif)

Expected result: Samples value remains as it was before.
Actual result: Editor displays samples value from previous animation.

Workaround: Click anywhere in the editor when this happens or switch objects via hierarchy.

Note: If you click anywhere in the editor value gets reset to original, but if you start writing it overwrites previous value.
Note: This only reproduces when selecting second object from scene view
Note: Also reproduces on Mac editor.

Reproduced with: 5.3.2p1 5.4.0b3 5.2.4f1 5.1.4f1