Letterbox Scale bug

I tested my game that has a window size of 480 x 640 on a Samsung Galaxy Note 2 using CocoonJS compilation APK.

Under project settings in C2, it was a Letterbox Scale. So, I was expecting the game will be in the centre of the screen since Samsung Galaxy Note 2 has an aspect ratio of 16:9 but the game is just 480 x 640. But, it turns out to have expanded outside of my layout + window size of 480 x 640 starting from the top, with a large gap at the bottom that was out of the layout. It works well in browser and node-webkit but doesn't work in the compiled APK. What have I missed?

*P.S. Tell me if you need more info about the game

"Compatibility

The following features are not supported in CocoonJS. If any of them are used, Construct 2 will print a message to the debug log saying that they are not supported.

• The form control plugins Textbox and Button are not supported.
• The XML object is not supported.
• The Facebook object is not supported.

- The letterbox fullscreen modes are not supported. If they are selected, it will fall back to 'Scale outer' mode instead.

- The Text plugin's 'Set web font' action is not supported.

• The WebStorage plugin's session storage is not available. Use local storage or global variables instead."

Either use crosswalks or design you game to adapt itself to multiple aspect ratios

I see... any news of support for Letterbox Fullscreen modes from Ludei? The game was made specifically to 1 screen size ratio and would not work with multiple screen sizes... I hope they would support them soon