Some blocks in Mounts of Mayhem: Dungeon Descent are black with vibrant visuals off or with smooth lightning on

This is just an example but if you download the free mounts of mayhem dungeon descent addon and try it out on preview, a lot of the blocks that are 3d in the dungeons like the statues in the wall and window frames, are completely pitch black but they are normal on the normal edition of Minecraft, this also occurs if you have fancy graphics and disable smooth lighting which is not a bug but is how I figured it was the issue. I will provide a picture as soon as possible