Reproduction Steps:
1. Create new Unity project
2. Open "System Preferences>Accessibility" and increase the Cursor size to max
3. Try to click with the Cursor anywhere, that only the tip would be over it
4. Notice that it does not interact
5. Try to raise the cursor a bit
6. Notice that cursor effect area is slightly lower than the tip (about 1-2mm)

Expected Behaviour: When Cursor size is increased the effect area is still the tip of the cursor.
Actual Result: Cursor effect area is slightly lower than the tip (about 1-2mm) when Cursor size is increased.

Reproduced on macOS with Retina display
Reproduced on versions: 5.5.4f1, 5.6.1p4, 2017.1.0b9, 2017.2.0a4