I think it has to do with technical glitches. My samsung galaxy Note 3 did support 4k setting one time for ultraflix but after the most recent update it defaulted to HD. I think some TVs are experiencing the same thing and I think that's the reason ultraflix has to revert back to mx player being required for ultraflix playback on Android and that could be the reasons of delay on samsung tizen, sony and others. Besides, ironPantz has shown MANY times over that Ultraflix video quality is hands down superior even at 4-6mbps and that debunks the 2k BS.