Seems like the profile to me.
Look at the light above the "MASTER" button, top right of your Kemper. When you play the Metallica one, does it stay red?
Mine does. Almost no where can I turn down the volume enough. You CAN turn the gain down all the way and STILL red light clip.
So I don't know what is messed up, whether it's the profile from the get-go or a change in the KPA's OS that did it.
But the good news? It's NOT you, NOR your KPA (I think)!!
I can't find the second profile you mention. Is it off of someone's website?
Some profiles can go red and still appear to work. Others digitally clip. You can tell by ear.