Ok thank you for your answer, but I don't get it ^^. Why the H9 doesnt understand Midi message via bluetooth ? Is it a security thing ? Because I'd really like to control H9 without Midi cable on my Midi controller and i don't want an iPad or iPhone on my Pedal board :).  Well if you have a trick It can be cool 🙂

No, it's not really a security thing.  There are different versions of Bluetooth available, and there aren't many Bluetooth footswitches in the first place, but the ones that are out use a different version of the Bluetooth protocol than the H9.  This Bluetooth connectivity stuff is still pretty new.  I would think with time devices will start working together as you described.