Buzz when Connecting TX6

Im trying to connect my TX6 to the MiRack iOS app in 12ch usb mode.

When using the audio in 8ch module, the sound comes through perfectly but I dont have access to all the inputs. When using 16ch audio in or 32ch audio in, the sound is distorted and there is a buzzing.

It would also be nice to be able to be able to select the input source for each of the audio in module ports