Crackling Noise On Recording Track

Update: A friend of mine bought a Behringer x32-Rack-Mixer + the Cymaticaudio – uTrack x32 Card and immediately got the same Problem – “Crackling Noise” after a couple of min. So we took the Card and plugged it into my x32 Producer – Mixer, recorded for 3 hours and found everything OK. My friend played around a bit and switched from 48kHz to 44.1kHz and the crackling Noise was gone.
Fazit: Currently the Issue only shows up on a Behringer x32-RACK Mixer with uTrack x32 Card running on 48kHz.