UR 12 with Garageband not working

Hi there,
just bought a brand new UR12.
But I cant record things with Garageband with it.
In the GB Audio-Recorder says: Press record to your signal from your USB Audiointerface…
…but there is no signal comming trough.
I tried all: iPad, iPhone, Macbook (here the UR12 is the selected in- and output device…)

Same goes for the GuitarAmp section…

What could it be?

Thanks a lol and Danke from Frankfurt

I have a UR12 and it works fine on my Mac Mini, except I am picking up both the channels on a single track even though the track is only selecting the XLR or line.