Unreal-SteamVR Alpha channel

Hi all
i know that android arcore need frame with alpha channel, but in
in the Nvidia cloudXR Android APK, used on many type of smartphone,
seems that every object from the “default Home” of SteamVR, every Unreal exported VR scene
and yet, the Nvidia cubes ar_test.exe included in the TestTools, is blended with the phone camera,
even if the project is set with rendering framebuffer in RGBA.
Unity exported scenes seems a bit less transparent than unreal, but objects are a bit trasparente too.
Others have encountered the same problem?

best regards. Alex

We found that the issue (in this case Unity Projects) seems based on the Andorid/ArCore Version

Same scene, same Windos10 Pro, same CloudXR server and clients and same RTX2080
On
Huawei P3 and some Samsung (A50 - Note 20 - Galaxy 20) with Android 10 and 11 on - Scene Objects and SteamVR Home have a sort of Transparency whre objects are opaque.
Redmi Note 7 and LG G6 on on Andoid 9 - Scene Objects and SteamVR Home are perfectly opaque

Seems that the Alpha Channel is readed mixed with the RGB info, because light/area are less transparent than shadows

Update @GJones-NVIDIA-XR-Team
Seems that old smartphone without ArCore “Supports Depth API” are ok
All Recent Smartphone tested with Deph API, had some mixed alpha
Win10Pro->Steam->CloudXR->smartphone (before uploading any scenes) .