Video streaming on Android and GearVR

I have followed this Live Training Session to learn how to stream a video from Dropbox or GoogleDrive in the UE4.

1/ I cannot get a video to play normally in the Editor if its resolution is above 1080p. In case the resolution of the video is above 1080p, the video texture remains black although no error is indicated on the console.

What should I do to be able to stream 4K videos ?

2/ This does not work on the GearVR, the video texture remains black even if it is low resolution.
Although the Mobile Preview ES2 works similarly to the Editor (videos in 1080p or lower resolution play normally, videos with a higher resolution than 1080p don’t play).

What should I do to make this work on Android and especially on the GearVR?

Did you find a solution for Android? I’m having the same issue…