I typically set my tuner @ 0 volume so I never use the Tuner button on my Kemper Stage. At some point during a show this past weekend, I looked down and saw a notification that tuner reference pitch had changed. I'm not sure if the left softknob got bumped while my volume was down and tuner was active, but it took me a while to figure out what was going on and in the heat of battle I wasn't sure how to fix it right away.
The potential bug I see is that when the expression pedal is down all the way and volume is at zero and the tuner comes up, if the reference pitch is not 440 then you have two softbutton choices: Default 440 hz, and OK. The problem is that hitting the Default 440 Hz button does nothing but make the screen go away. It doesn't fix the tuning reference. If you hit OK, then you just verified that you want the new (wrong/unintended) reference pitch.
Upon thinking about it after the show I came up with the idea of hitting the Tuner button. It pulls up the same screen with the same two options, but the Default 440 hz button actually fixes the reference pitch as intended and all is right with the world.
I think what may be happening is a conflict between commands while in tuner @ zero mode: 1. when tuner is at zero you can tune, but if you hit any/another button it makes the tuner window go away so you can make edits and such to fx slots, etc. 2. hitting Default 440 button isn't getting through because of the 1st "rule".
The current workaround is just to use Tuner button to access the Default 440 reference pitch correction, but it seems like having the option to hit it in tuner @ zero mode should also work, but doesn't.