As you see, I'm making a jacket, I flipped over the collar, hopefully two fabrics should stick together each other but it looks like there is a big gap between them. I tried to put it down again and again, but it kick it up. It's like there is an invisible balloon between them. I thought it must've been related to 'Add'l thickness - collision' or 'Add'l thickness - rendering' so I scaled up and down, it doesn't seem to change it at all. I wanna reduce the distance between two fabric. What should I do?