All of the Rogers Key2's spacebars I've observed are loose and therefore make a clacky or rattling sound when gently touched i.e. not depressed.
On two of the Rogers units at the office I pushed the opposite ends of the spacebar down quite hard and held it down for a few seconds. On both units it seems to have eliminated the clacky or rattling sounds. The bar still feels loose but it's not making the noise.
Let's see if it holds.