If you load a preset with a looper on your H9 you can no longer use your aux switch to switch presets. To jump to another preset you have to adjust the preset with the wheel on the pedal by hand. It can be a fail for some ways of use it in live situations.
I'm not sure I understand this. There are a couple of different pedal functions that you can assign to an AUX switch to jump to the next preset; there's preset up and preset down and there's also load next and load previous. Which pedal function is not working for you, and what are you seeing happening when you try to use the AUX switch when the Looper is loaded?