Dizzy Baby... Knot


I feel a little silly bringing this up. But as I’m going back through the check list of tricks, I see that I never really got the full trick down. I can go through the whole trick, but I get a knot at release every time. I assume I am pinching the string, or holding it the wrong way. Can anyone give advice on how to clean this up? The video here is not quite clear as to which way to pinch the string. Thanks.