I have the same problem with my KE88. The lowest G key hits full strike, sometimes random/multiple hard key presses, or it'll even re-hit the key when I'm letting go. It's as if the inner switch is failing or not working correctly. If I set the keys to "LIN" instead of LOG it seems less noticeable, but it still does it.
If anyone has any ideas how to fix this, please share... TIA.