Nav mesh generating above tile map in paper 2d

So I’ve been trying to get nav mesh’s to work in paper2d side scroller. I’ve almost got them working. I’ve been messing around the my tile maps collsion thickness but that doesn’t seem to do anything. I’ve been messing around with stuff in my recast nav mesh settings. I was able to lower it with the cell height setting but I can’t put any lower than 1. That just barely isn’t enough so how else can I lower a nav mesh?