Qu drive + mac USB routing (Qu pac)

I’m recording a gig on the Qu drive and simultaneously routing audio to a Mac laptop with Mainstage. I’m trying to make use of all 18 recording inputs on the Qu drive and there is a source I don’t need to record but I do need to route to the macbook. On the Qu Pac this is channel 6. In order to not record this input I thought I could use a different USB “bus” (above 18). When I go to the second page of USB routings and change say the channel 23 box to say 6 and then in Mainstage route from input 23 I don’t receive channel 6 in Mainstage. How can I use the high usb channels to route mic channels avoiding the Qu drive?
Thanks

Solved! Apologies pilot error.
I used a different USB bus and audio connected correctly

I have so far not managed to find a compatible drive for recording. I started with a SanDisk Extreme portable 1TB drive - not compatible. I have just tried a SanDisk Ultra Flair USB 3.0 flash drive, 64GB, up to 150 MB/s. This time Qu-16 didn’t say not compatible, it said it was checking the drive and this went on for several hours until I gave up! Can someone out there recommend a drive that does actually work? I would be most grateful.
Many thanks.