H.265, 3840*2160P @60Hz, Dolby TureHD 7.1 48.0 kHz video keeps audio break (or pause) and sometimes even video goes black. I thought there could be a problem with USB connection speed and I copied the file onto the internal HDD. Nonetheless, the symptom doesn't change. Of course, my receiver is full 4K compliant, MRX 720 and all HDMI cables are 4K as well. I have the most up to date firmware installed. I guess I will have to go to kdlinks a400 unless there is a solution.