[UnrealEngine4][Help] Bad graphics quality on tablet, runs fine on PC

Hi all,
I have just finished my game for mobile. It went marvelously on PC, but as soon as I try to run it on my tablet (Cube U27GT-s, android 4.4.2, using UE 4.12), I get very low res and bad quality graphics, and some of my buttons aren't working either. The game uses widgets only, it's a simple puzzle game. I did try setting the scalability setting to Epic. I did ask this on various unreal forums, but to no avail. I'm using the android sdk provided by epic games that came with the download of UE.
I have no idea what causes this. Thanks in advance for the help.