Android Handheld.PlayfullscreenMovie not working from Cloud Build

so.. when i build directly to my android device - this line

Handheld.PlayFullScreenMovie("ladybird.mp4", Color.black, FullScreenMovieControlMode.Hidden, FullScreenMovieScalingMode.AspectFill );

works fine.. But when the project is built via the Unity Cloud Builder and i install the .ipa on the same device - the video will not play.

the only thing i can see in the logcat is E/MediaPlayer(29046): Unable to create media player

if i change the pathname to Handheld.PlayFullScreenMovie(Application.streamingAssetsPath + "Ladybird.mp4"...

then it doesn't play when directly installed onto device... haven't tried this from the cloud build yet.

Thanks for any help...