ii have a Behringer UMC404HD and whenever i leave auria and switch to other apps (simple things like safari)the audio gets distorted quickly (sounds a bit like bitrate/samplerate degrade) and the audio"slows down"(wav loops,no timestretch).
A simple plug in/out of the interface solves the issue (t's amazing that you can even do this while aurias sequencer is running
It won't happen when i switch off background audio operation.Also this does not happen when i use the interface with other apps like Cubasis or Audioshare (with background audio on etc.).
The UMC204HD shows the same behavior (bought this first but replaced it with the bigger one) alhough i have no problems with the Roland UA-22.
I tried changing the settings for core audio but switching to"multiroute"does not produce sound at all.But i can see the incoming/outgoing signals in aurias mixer.
I restarted/replugged everything whenever i changed a setting and had an eye on the In/out matrix as well.
And it makes no difference if i use a hub or go directly into the ipad (interface has own power)
i'm still on ios 9.3.5