This might seem like a small point, but it’s not.
I advocate, and many current instructors advocate, placing the ball in the center of your stance and keeping it there when you hit your irons.
But just saying “the center” isn’t really that specific.
The three photographs below all show a ball intersecting the center of a stance (yellow rod), but the ball is in a different place each time. Each ball is offset from the other by about 0.4 inches. This is not an insignificant difference. It is all the difference in the world.
You can’t have the ball here this time, there the next time, and someplace else the time after that and expect to make consistent contact with the same swing.
Experiment with where, exactly, in the center the ball needs to be for you to get ball first, ground second contact.
Once you have found that spot, memorize it and put the ball there EVERY TIME, at the range or on the course.