Hi, Roman, sorry to hear your problems – I’m sending PC changes to Fractal MFC101 MIDI board (I don’t own AXE FX but several MIDI driven effects / Strymon, GCX switcher, RJM amp Gizmo) and that works great for me. But anyway, have you tried monitor MIDI messages from MIDI output of LP16? (play a song from USB while connecting MIDI out from LP16 to your PC and runnig e.g. MIDIOX). You should see your messages there, are they correct?