Whenever I import maps a problem occurs. White lines show up whenever there's open space, (I followed this tutorial https://www.youtube.com/watch?v=18x1vCrS7Tg&t=40s) and I'm pretty sure this kid has no idea what he's doing.

Does anyone have a method that does not render these white lines and actually looks like the maps? Please include a video/ guide on how to do so.