1. Download the attached project
2. Launch the "Core.app" standalone (or build a new one with Resizable Window enabled in the Player settings) on a retina-enabled display (in this case a Macbook Pro was used);
3. Select 2560x1600 resolution, full-screen mode and launch.
4. Observe the reported resolution (near the mouse, after graphics API) not matching the selected resolution.

Note1: The problem only appears when the "Resizable window" is checked in Player settings.
Note2: Launching in windowed mode also gives incorrect resolution, but instead of decreasing the resolution is stretched.
Note3: The problem only appears in Retina monitor/display.

Regression:
Bug introduced in 5.5.0b1.
No repro in 5.4.4p4 or 5.4.5f1.
Repro in 5.5.0b1, 5.5.2p1; 5.6.0b10; 5.6.0f1