Mouse Input in Android

Hello,

In my game, I use Left Mouse Button to Attack, and Right Mouse Button to Defense.
Everything works great with StandAlone version.

But in Android version, I connect a mouse to the phone via Bluetooth, however, Unity detects the RightMouseButton as KeyCode.Escape , not KeyCode.Mouse1.
(but LeftMouseButton works great)

How can I get the KeyCode.Mouse1 on Android? Anyway to get native physical input for mouse from Android OS?

Thank you.