I'm not following the logic on this. I plug EMG active pickup guitars into the Aux. input with no problems ( those pickups have built-in preamps). Also plug a bass with active preamp into aux. The guitars sound better to me this way.
I would also suggest: power off/on again after doing the global / factory reset. This should take care of "rebuild preset" message. I usually do this twice to verify Helix powers-up correctly.
I am curious about the whole "export / import" aspect. We basically export setlist with the current editor app.(2.01) Then update to a new Editor app.(2.10)/Firmware. Then import "old" setlist into a "new" editor environment. I'm not a programmer, but seems like a situation that can cause problems.
you said grok, :D .
I'm absolutely thrilled with my Helix! Some of my favorite user created presets only have 1 amp, 3-4 efx, and they sound awesome! Thank you for a fantastic product