MediaFrameReader, no FrameArrived callback

[Xispeo]

Hi, I use a Hololens 2 with Unity 2022.3.69 and Visual Studio 17.7.6
I tried every single code I found on the web to capture RGB frames, code launches the MediaFrameReader but the callback never activates...
I noticed that I cannot select the VideoPreview stream and am on the VideoRecord stream:
var mediaFrameSourceInfo = mediaFrameSourceGroup.SourceInfos[0]; is NOT ok since
var mediaFrameSource = mediaCapture.FrameSources[mediaFrameSourceInfo.Id]; will fail in finding the forced ID in the FrameSources map...

I added to the manifest the webcam and all, and I try & fail since a whole week...
Is there any regression currently ?