Xert needs control in order to signal the workout changes. If you meant Bkool controlling the Kickr,
is there a setting on Bkool to disable control of the Kickr 5? Since the Kickr 5 has 2 bluetooth connections it should work if you can disable control.
Does the Kickr 5 broadcast as both a trainer, and also as a power meter? And does Bkool let you just select the power meter? If so, then it would have no ability to control the Kickr.