Rendermode=gpu ignored? in Android 5.0

Problem Description:

On some android devices, application falls back to cpu render mode instead of GPU mode,

despite declared in -app.xml (<renderMode>gpu</renderMode>).

Profiled with Scout CC and confirmed x5~x20 increased time consumed in rendering,

indicating AIR runtime is rendering the application's DisplayList  only with software mode.

Steps to Reproduce:

https://play.google.com/store/apps/details?id=com.ggee.vividruntime.game_ticket_1715&hl=ja

Application packaged with AIR SDK 17.0.0.124,

Severe fps drop observed on following devices :

1. HTC Butterfly J HTV31 (Android OS v5.0.2)

2. Nexus 6 (Android OS v5.1.1)

3. Docomo F-04G (Android OS v5.0.2)

Actual Result:

Severe framerate drops to <15 on main menu screen.

Expected Result:

Should be able to achieve targeted 30 frames / seconds with devices listed.

Any Workarounds:

Does not happen in APK files built with AIR 16 build 292.

Does not happen in android devices with OS versions under v5.0