Hey,
Would love to try and help you out. It seems those are 2D planes, correct? There might be an issue with Nanite converting 2D planes, even though it really shouldn’t. A couple things you could try. Could raise the amount of edge loops or turn them into cubes by adding some height to them. Sorry that isnt a one click fix, but maybe a work around.
Let me know if either of those work, if not we’ll try something else.