Noise when using electric guitar

Hi community,
Though the ICA4+ is a huge help in my set up and works like a charm now, there is one thing that I could not get fixed yet.
I am having loads of noise in my guitar signal, when I use gain pedals or amps at higher gain settings in BIAS FX on iPad

My set up:

ICA4+
I Pad 4 running Bias FX
iMac late 2013 running garageband.
Several Framus custom made guitars (noise free on my all my real amps, even at higher gain settings)
Guitar goes into ICA4+inout channel 1, is being processed in BIAS FX and then routed to Garageband on the iMac.

I am assume there is a grounding issue somewhere, even though I connected all devices to the same power outlet/circuit.

Does anyone experience similar inconveniences and found a way to solve it? By using a DI Box perhaps?

Thanks in advance,
Simon