Dumb question: Have you tried to turn up the noise gate?
Yep, my problem is when note is sustaining, there is some weird noise, like hiss or something like that. Played whole my life on tube amp, I did not have that problem, even I think Kemper is a bit noiser then amp. In AS i can't play chord without that weird noise, I have even downloaded Tone Junkie preset, same thing. But, I would be much happier if I could get rid of that noise from all my other profiles, I don't use AS so often.
Addition: I moved to another place just to excute problem with electricity. On every place same thing..