That’s usually a sign of just a little bit of warp. As little as a mm can throw that off.
You might want to try printing a few of these pins…I swear, they hold down the material like nothing else, including magnets, tape or anything else I’ve tried so far. (You can break them off if you are not careful…be gentle sticking them in and pull them straight up when you’re done.)
You might notice a real difference. (I’d like to kiss the guy that posted them.)
