It's okay to be flexible, but try to keep it consistent. And stay away from placing the ball too far forward in your stance.
Hitting better chip shots requires a few fundamentals, most of which get overlooked by beginner and better players alike. Let's look at a few and get your chipping back on track.
This seems like an obvious mechanic, but choking down on the grip actually does a lot more than simply get your body closer to the ball to make a delicate stroke. Choking down also counterbalances the club, meaning added weight above the hands work to make it easier to make less than full shots without flipping the hands over too soon. As for your body, remember as you choke down: Don't hunch your upper body. Instead, choke down with your hands, and get your body lower by adding more flex in the knees, as opposed to hunching over.