USB is filthy dirty, the power portion (5V etc) generates a lot of noise from most PC systems, and also causes (in Australia at least) some kind of grounding loop issue depending on where your music bits and your computer bits are plugged in (same line, diff line etc). Specifically the noise subsides mostly when you touch the strings/pickups, whereby grounding them.
EDIT: After watching your video it sounds to me like with the Kemper connected something causing activity on a timed interval + the Kemper might be causing data bus saturation, or power droop or just power noise interference. Juggle ports furiously
There are a few ways to tackle this massively annoying problem. Here's what may work, at the very least you can eliminate causation using some of these things:
- Run an extension cable from an outlet on a different circuit to your music gear. How to know which outlet is on what circuit (in Australia we have usually a couple of power, lights and other)? That I don't know but try a few, probably an opposite outer house wall outlet.
- Unplug all your other USB devices apart from the absolute minimum then move the Kemper connection around. I had nothing but issues with my Scarlett 2i4 popping and shitting itself until I found a USB port that was situated on a less busy USB hub/bus from the mainboard. Most bigger PCs now have a lot of USBs but they are separated by virtual hubs etc internally and whilst 1 port might have lots of transient power noise another might not. You can see the power usage and bus usage in the device manager on the PC as you plug and unplug devices.
- Buy a reasonable brand external USB hub that comes with its own power, then you can try to isolate that PSU or move it onto the same outlet as your music gear depending on the noise and issues, power and/or grounding. If the port you uplink the hub into is the prime source of the noise then this may not help, you might need to juggle ports.
- There are (expensive for what they do) USB power isolation and cleaning inline solutions out there, do they work well ? I don't know.
Once we see off USB in the coming years we'll all be better off, its a filthy, filthy little hole that USB, the sort Dad said to steer clear of...
GOOD LUCK FIXING.