Maybe I need to explain my intend.
The FX3 is connected to an ipad via USB,
the iPad is my multitrack looper (group the loop)
The sound is working fine, but I want to controll
the app/ipad with a foot midi controller.
In the app the FX3 is shown as a midi port but
the midi commands aren't passed.
I have also an USB interface (Focusrite Clarett)
with midi port and USB, this is working fine.
But the sound quality is far less then with the
FX3 connected directly to the iPad.
I hope this will explain my problem