That button is secured by a wood screw that is tightened only enough to hold it in place. Any movement in the wood from temp or humidity and any compression of the felt washer that fits between the base of the button and the heel surface will allow the button to be turned. The remedy is an ever so slight clockwise turn to the button’s hold down screw. This will prevent it from turning, rattling or further disrupting you peace of mind.
Hi from all the crew!