I got CC Mode "on" & working easily with Auria Pro on an iPAd 5th Gen (software 13.1)..
So the graphic illustrates a bright red on button in the control window.

Then I think after I deleted Auria Pro and re-installed things stopped working.
Or perhaps some sort of iPAD issue..

I enable CC Mode but it seems to reset.
So now the red button is a dark brown color and I get no audio into
Auria Pro.

As soon as I unplug from iPAD the on button turns red again.

Somehow after an hour of plugging -unplugging it started to work.
Following the procedures as written by RME..

UPDATE: after plugging into an iPhone same problem CC Mode seems to shut down...

Any help please & thanks you!!

UPDATE: it was Auria Pro .. an iPad setting: Privacy/Mic/On