Hey Peter,
Thanks for getting back. Weirdly, doing the exact same thing today, it's now fine. Unsure whether it was a thing with the particular patch I was using, but now all back to normal and can't recreate the problem with any patch/rig.
I restarted the kemper a few times as well yesterday before posting in here, so not sure what would have changed over night. But happy it's all back to normal!