Reproduction steps:
1. Open the "bug.zip" project
2. Open the "test" scene
3. Make sure you can see the Game view
4. Maximize the editor window
5. Restore down the editor window
6. Maximize it again

Actual result: Elements are out of their original position
Expected result: Elements retain the same position as they were after step 4

Note: Resizing game view, opening a new window in the editor or moving the button resolves the issue.

Reproduced on: 5.5.0b6, 5.4.0p3
Not reproducible on 5.3* and 5.2*, 2018.3.0a1