It's a year later. I had the problem off and on. A couple of patches ago, it went away. It came back with the latest software update.
None of the tricks work now (recalibration, unplugging, -12db, etc.). The volume goes down, but not all the way to zero even when I calibrate.
When I calibrate, it says zero, but there is still sound coming thru.
I had this exact same problem, too. Here are the steps I took to fix. With the Kemper powered on and USB A-B cable plugged in (I have Kemper Stage, if that matters), I went to Device Manager and uninstalled the "Profiler" from both the "Audio Inputs and Outputs" section as well as the "Sound, Video and Game Controllers" section. Each section had two instances of a Profiler device and I uninstalled both in each section. Then I closed Device Manager and powered off the Kemper. Then reopened the Device Manager and Powered the Kemper back on (with USB still plugged in). It automatically reinstalled the devices--and named slightly differently now.
It went from "Digital Audio Interface (Profiler)" to "Digital Audio Interface (2-Profiler)". Not sure if that matters, but the uninstall of the devices and reboot seems to have done the trick. I did not need to reinstall the Rig Manager software.
