Get USBDeview (
https://www.nirsoft.net/utils/usb_devices_view.html) and see if when you plug in the K it shows up as an unrecognized device. If so then uninstall all the similar entries and reconnect. If that doesn't cut it then try:
a. re-seating the grip - I kept getting odd connection behaviour and I think it was all down to dirty contacts between the base and the grip (also if you pick it up to move it around make sure you never do it by the grip)
b. enter calibration mode (hold eject and the flaps I think while it starts up)
c. resetting the device (there's instructions of how to do it by shorting two points on the board IIRC)