The tap tempo of the kemper, or rather, everything about the tempo in kemper is the biggest disaster in history.
I've been testing for a year (including external controllers, synchronizing it with a continuous and precise external tap ... etc etc).
It is a disaster.
I never heard about that.
I've had a few devices with Tap Tempo and they all worked perfectly (Boss, Trex, TC, Fractal...). And I never heard anybody complaining about this problems with Kemper gear, so I'm surprised.