I was using Cubasis with a USB mic which was connected via a USB c hub. All equipment was connected before starting Cubasis.
Headphones were plugged into the USB mic for monitoring
After about one or two minutes, crackling started when playing back recorded music (at that time, one short audio clip and one short midi clip). Like a reduced bitrate. Regardless of the midi instruments used (auv3 plugin or micrologue). I tested this a few times and got the same glitch every time. It worked fine in another DAW that I tried (to see if it the USB mic was actually working).
Cubasis used with latest version
iPad pro 12.9 2018 (iOS 12.4)
USB mic: blue yeti nano
USB c hub: hyperdrive
Thanks for advice,