USB source power from even that Anker might get a little thin but let's say you checked their site and it's fine. Then that cheap player can be an issue. I find most of them play a fraction of the files that folk collect.

This is all about the video encoding which I won't get into here. It's a well done discussion on the web. So you could connect it up and get royally cheesed about how little plays.

I suggest you re-cycle an old PC or laptop. That is how I solved this. I used my 2009 Sony Vaio laptop and it plays every file that VLC Player (google that!) can play at 1080p without a hitch. There are other players like Kodi but I like simple and always works.