It's even more noticeable/frequent with round laces so that's what makes me suspect you might be a victim of this.
Comparison To Other Regular Shoelace Knots
It was much easier to prove that Ian's Secure Shoelace Knot is more secure than any of the regular shoelace knots. Using a pair of shoes with round, slippery laces, I tied one with my Ian Knot and the other with my Ian's Secure Shoelace Knot. Despite tying both to approximately the same average tightness, the Ian Knot came untied two or three times a week whereas the Ian's Secure Shoelace Knot never came untied.
https://www.fieggen.com/shoelace/secureknottech.htmI've even tried tying his shoes myself (so I know both the knots are pulled really tight, and that the loose ends are the same length as the bows). Even so, somehow the ends get pulled hard enough that they end up undone.
(Somehow for him even the Ian secure knot doesn't guarantee a full day without laces coming undone.)