Steinberg audio interfaces with Cubasis/iPad support

Hi! I have a question. I use different class compliant device with my ipad 4 generation. I use : audiogram Yamaha 6, gn2u zoom. These two interfeces are recognized by ipad perfectly , I use them with garageband,sunrizer,animoog,bs16,Ielectribe and others. But when I try to use my devices with cubasis … Playback audio seems to be afflicted by a sort of " bit reduction effect" on the output of cubasis. Then if I exit cubasis all the audio sistem of ipad have the same problem. So I’ve to unplug and plug again the interface to work properly.
This problem appeared after 1.6 release of cubasis. Before all seemed to work fine without any issue. After the recent upgrades cubasis become unusable with generic class compliant device . Can you help solve this? Thanks, leox2012.