In my case (I opened this thread), I was ready to sell my Kemper Stage over this,, but I eventually "solved" the issue myself... I found Kemper support to be difficult to deal with and they basically had me download a few free DAWs, some of which allowed the ASIO driver to load, but work very poorly, some of which displayed the same behaviour as my DAW (Cubase).... They asked for details of my DAW, including the exact version number which delayed the process for a day because I wasn't with the machine. I supplied all the information and was informed that they had tested it on their machine with my DAW and it worked, so they blamed "something at my end" ... it later turned out that they were testing on a completely different version (I was on 12, they were testing on 13) yet still they blamed "something at my end" but offered no constructive advice on what it could be or how to diagnose it.
To shorten the story, my later discovery was that the issue which I described in my first post occurs with any DAW which is set to "run as administrator" but I have used several ASIO drivers over many years and none of them have had an issue with this (including Line 6 Helix drivers) so I still say this is an issue with the driver.
Once it was working, I found the driver to work poorly, with the buffer size unable to be changed and the fact that with Cubase, you must use the Native Asio option, which means the Kemper/DAW and other sounds such as Youtube cannot coexist, and require switching via Rig Manager every time I want to use one or the other.
After weighing up the idea of selling it and moving on to something else, I decided that the only alternative which sounds as good would be QC, but it lacks foot switches in comparison to the Stage and its power supply and size makes it resemble a toy in my mind, so I ended up buying an Audient ID14 interface, a headphone splitter box and a Mackie Big Knob, just to get the functionality which the Asio driver should have provided. I'm totally happy with the result, but not happy about the time and extra money it took to get there.
Thanks to everyone who tried to help here along the way. 🤘