It's been suggested that this only happens on the first midi programme change, if so and it doesn't repeat then as part of your pre flight checks at a gig you could send a pc, via a midi changer and call out a preset say then when the bug appears simply override it by pressing the yellow lamp.
I lodged a ticket with h&k on their website and the representative from jhs in the uk suggested after I provided the serial number that it was an early release and that I should send it back to the supplier (Thomann in Germany) for swap out. Thomann are saying it's a repair and that they'll send it to h&k, it could be away for a month.
So naturally I am not delighted by the prospect but hate things not working as they should.
However before I go down that route I thought I'd try and identify what's happening and what is not. For me this appeared whether the iPad app was connected or not.
What I have noticed that I can replicate the issue if I change the amp channel on the app but it ONLY happens if the preset is one that I've created (saved and stored to a new location above the factory presets i.e. 91 and up). I stepped through all 90 presets and not one of my factory presets triggered the condition.
I then found that if I entered say preset 91 and saved it again the bug did not appear again, whether I called it from my midi switcher OR manually. Also I can force the condition if I select an empty preset (for me just now from 102 and up).
I've power cycled the amp and reconnected the app and it seems to be fixed but only for the newly created presets not the empty presets...
I have never taken a backup of the presets but did so and saved back to the amp, now all of the other affected presets seems to have righted themselves and the power soak may bug is no more. (Apart from the empty presets that is)
I'm not entirely convinced.
I'll try and break it again tomorrow but is the issue perhaps related to how the presets are saved? Not sure if I created these presets from a factory preset when the global power soak was enabled perhaps and now it's off the amp is protecting itself/ or the user perhaps?
Can someone try selecting an empty preset and confirming that the power soak mute is enabled?
Perhaps this "bug" is simply operator error?
Let's hope so, but I might still try and talk to h&k technical not just their handling agent in the U.K. And see if they'll divulge just what the firmware update actually does....