Can't record multiple tracks

Hi All,

Have an issue which I hope you can help. I am trying to record 2 guitar tracks simultaneously on GB. The source is Line 6 Pod Go which I'm using as the audio interface. One track is 'wet' and the other is 'dry' by selecting the appropriate PG usb inputs. I have enabled recording on both tracks. I have clicked 'monitor' on both tracks as well and individually they have an input signal.

When I start recording, only the 'çurrent/slected' track has input and record. How do you get GB to record both tracks simultaneously? I'm using GB 10.4.6.

TIA.