isn't it hot knob and right foots witch key– not hot knob and big button
That restores the system settings. The big wheel and right footswitch restores the system settings and the factory presets and is a bit more thorough.
When you go into the system mode on the H9, do you see the right serial number there for your unit? To check that, you press the HotKnob and right footswitch to go into system mode, scroll to Utilities, press the HotKnob (I think) to go into Utilities, scroll to SerialNo, and press the HotKnob to go into the SerialNo setting. Pressing the HotKnob and right footswitch will take you back out of system mode.