https://www.fieggen.com/shoelace/ianknot.htm
I’ve been doing this for nearly 20 years.
Not sure why, but single knots always come undone for me pretty quickly - including the Ian Knot you linked. I used to do a double knot and now the secure Ian Knot.
Since you've read about knots I'm sure you know this, but it's worth mentioning for others in the same situation - if you find your laces come undone very easily with a simple traditional knot it may be that you're not balancing the starting knot and the finishing bow, leading to a "granny knot" - https://www.fieggen.com/shoelace/grannyknot.htm