Not sure if you got an answer so far, but I understand on your post that you see detriment on the quality when you are medium to far away of the actor.
First, as you said this is a demo project, try first to check this option, if you have it in low, materials will look crappy even in epic or cinematic mode.
, if you want to dig further:
Did you check/customized your level of details (LOD) by any chance? unreal by default calculates LOD based on distance, to put it simple, if you actor has 10.000 poli, when you are far, unreal will reduce polis to 2.000, will be quicker but you probably will see it fairly ugly.
What you can do, if you have a particular mesh that you would like to remain it in the best quality, go to your MESH settings, and configure it to be always LOD 0. Also you could try to play with the automatic LOD setting, it works very well, unreal will decide which LOD technique to use if you tell what kind of actor you try to develop.
I strongly recommend you to use LOD group first, most likely will solve your issue.
Good luck.