Adobe Premier Pro CC 2018 Chopping Preview Issue

[Mitchell Nossa]

Hello everyone, I refer to this forum since I had some problems with Adobe Premiere, I tried to find solutions online and also in these forums, but it seems that my case is something curious or maybe I can not find the right way to find a solution .
The problem is to see the preview of any project, I've tried the most things and most common so that the preview is not cut, but nothing works (create proxies, reduce the resolution, increase memory, render the where I'm going to work, etc.) and it's quite frustrating because in the video that I attached you can see how the audio is also cut and the video is very difficult to work in this way, I would greatly appreciate if someone can help me.
P.S. It is not a lag of the computer, since I have two SSD, the core i7 8700k and a gtx 970 FTW, apart from this, other programs load perfectly and do not have this kind of problems.
Beforehand thank you very much.

[Mitchell Nossa]

Hi, the footage is from my cellphone and is .mp4 from a huawei mate 10 pro at 4 k 30 fps H.264

1. the proxy setting is H266 1280 x 720 
2. yes, is update and i reinstall 
3. yes.

[Mitchell Nossa]

 

Ok. I do not know how this works, but when changing the playback device over the speakers the preview is not cut anymore, VegetableStu thank you very much, but I think we will all be left with the incognita of why this worked.