Preventing M: S from being used as an audio interface on the iPad?

Hi there,
short question since I have not been able to find a solution in the manual.
I am using my M:S in conjunction with my iPad via USB. Both M:S and iPad are connected to my mixer via audio cables. Whenever the devices are connected the M:S acts as an audio interface and the internal audio out of the iPad is deactivated. I tried to find the settings in the M:S circumvent this without success. Setting INT out to AUT did not do the trick.
I want to send audio from M:S to iPad for recording and I want to send clock and start/stop from iPad to M:S over USB. But since I want to add an external audio interface for recording hardware synths and guitars I do not want the M:S to act as an interface.
Do you have any idea how to hinder M:S acting as an audio interface?
Thanks for your help.

i think on ios you can only have one audio interface at a time… so, if you want to stream audio via usb from m:s to ipad, it is not possible to use another interface at the same time…

maybe try connecting the interfaces in different order and see, which is used by ipad?

Thank you for your hint. I will try this as soon as my new interface arrived.