that doesnt matter, k60 and k90 arent initially compatible for the very same reason, which is the high key rollover through usb
any keyboard with an usb key rollover of higher than 6+4 needs the two adapters in the topic i posted
with those adapters they do work
it was already confirmed for a bunch of high key rollover keyboards such like k60, k90 and some noppoo choc keyboards
i am pretty sure that either your adapters dont work like they should, arent the same as in the links, or some driver software changes have been done to the keyboard that make it incompatible (eg polling, key assigns, macros...)
dont forget that the xim most likely still needs the keyboard to be attached to the prefered keyboard usb port