Help with box brush surface material not showing up

I am new to Ue4 as an engine, and the forums - so bear with me. I am attempting to make a road, and the way I think would be easiest is by using a box brush, so I can change the UV’s to not be stretched. So, I apply my basic road material (One of the Quixel Megascans I imported), onto the top side of the box brush, and it did not show. I did a bit of research and couldn’t find anything as to why this could happen. I looked under the geometry tab and clicked “clean geometry materials”, because that is about the only thing that I could find as a fix. I’m sure I am doing something wrong because there is not much on this, but as I said I am new to Ue4 so it is probably my mistake. If anyone could help me out here, I am happy to give more information if needed! Thanks.