I doubt this is a bug, more likely it is "authentic." But... On amps where I use high cut (e.g. Morgan, Maz, etc.), I find that I can't hear much of an impact at all until I get the high cut control up to around 7 or 8. So finding the sweet spot often has me setting that around 9 or higher. Not a big deal, but it does make the window of adjustment very narrow indeed. That actually makes it harder to dial it in by ear, because tiny changes of the control create big tonal changes by the time you are hearing it have an effect.