Is that front to back in the middle?

If so, stop the "up" or Down" deployment and inspect the underneath surface of the boot lid. It looks as though there might be some type of foreign material stuck there.

Or it might be some grit in the bottom of the storage through where the top lays. You can easily see this area when it is in the "Goal Post" position.

Other than that, I don't have a clue.

Not an uncommon problem for me.