I have recently been having this problem but G# and A# below middle C. I will be opening the piano to replace a couple of cracked keys and at that time will check the silicon lubrication of the rubber boots.
Wow. Never saw this in box the it came in. I never bought a stand since I have one because of back issued I play standing. I will check with the retailer. Either way I will need 2 new keys. Thanks for the picture.
My 560M is less than 3 years old. I have 2 cracked/broken white keys. A3 and G3. I am not a heavy player. Has anyone had this issue and can these keys be ordered separately?