The only odd Kapex/vacuum behavior I've seen, and what your dealer might be referring to, is that my Kapex didn't work well with my old Porter Cable auto start vac. The suction was ok-ish, but the laser on the Kapex actually kept the PC vac from turning off when the Kapex did. That helped push me to the CT36 with the larger hose to deal with the Kapex, and I moved the PC vac to other jobs.
So - the opposite of what you're asking, I guess, but maybe related?
So - the opposite of what you're asking, I guess, but maybe related?