5.6.0f3 VideoPlayer using URL fails to play

Hi all!
I have to say I was really excited about launching of 5.6 but my enthusiasm slowed quickly after my attempts to make web video work with unity on mobile platforms (android for starters)

On Android when using embedded video file with the new video player everything works fine (on Galaxy S7 & OnePlus 2). But when switched to URL source strange thing happens. In the editor - everything is also fine, but when deployed to device video playback is unacceptable. It starts to play and goes for about couple of frames and then freezes for a very long time. It is like 10s of waiting and 0.5s of playing. I've checked it both via local network & web (while using 100mbps up/down link) & using cdn and the result is always the same. Source video is quite big (4k) but when embedded it plays flawlessly. Also it doesn't depend on graphics api used (tried both with vulcan, opengl 2 & 3) or virtual reality support (tried both oculus for gear vr & cardboard).

example video i've dealing with is located http://horizon-7723.kxcdn.com/Rig1_001.mp4

Anybody experienced similar issue?