Steps to reproduce:
1. Open user attached project
2. Select Canvas -> Image
3. Clear the keyframes in the timeline window
4. Add a keyframe of 0 rotation at 0th frame
5. Add a keyframe of 90 rotation on 30th frame
-- Play through the animation - 0 rotation becomes 9
6. Fix the starting rotation by entering 0 and play the animation again
-- Animation values become unpredictable

Expected behaviour: Object rotation has an animation 0 -> 90 degrees
Actual behaviour: Start rotation resets to 9, fixing that makes the whole animation go through negative values 0 -> -180 then instantly to 180 -> 90

Reproduced on: 2017.1.0f1, 2017.1.2f1, 2017.2.0b1, 2017.2.0f3, 2017.3.0b4, 2018.1.0a1