The problem exists in every rig.
So the sensitivity of the knob is far to high.
How about your monitor's input attenuator? do you have it wide open?
Turn it down... like to may 1/4. Does your kemper's monitor out still behave the same way? You don't need to turn the monitor's level all the way open to achieve full power.... Kemper should be able to drive an input into clipping with ease. The level knob on a powered monitor is an input attenuator... not a volume control.