I have checked three app on Android (Nexus 5)
- A new Unity pure project and run on Android.
- Vuforia Android Sample package (https://developer.vuforia.com/resources/sample-apps/features#sampleAppModal)
- Vuforia Unity Sample package
Only "Vuforia Unity Sample package" makes Software buttons (BACK, HOME, MENU) turn off backlight automatically.
Though those button still work when user touch them, they are dark and invisible, so that user might not be aware to use them.
Please help find out whether there is any configuration inside Vuforia Unity package cause the issue, and suggest a solution to make it work as normal Android app.
Attached two screenshots.
- android sample - good - backlight of buttons are ON.
- sample_unity_package - bad - backlight of buttons are OFF.