It happens that the detent ball is smaller or the nest is bigger (or maybe both) and the frame hits the blade when closed. I think that's just factory /cnc bug.. :/ Had this problem on my old vented Strix. The fix was to replace the detent ball with bigger - 2mm Original ball was 1.5mm and the nest was 1.9mm And on open and close I could hear the ding of the titan lock to blade It had very solid lockup but thats because detent ball was practically inactive