Crackling Noise On Recording Track

Update2:
So I sent my x32-Rack Mixer with the u-Track-x32 plugged into x32-Rack-Mixer for repair to Behringer.
Got it back after 8 weeks, but nothing changed.
Repro:
If I plug in my Kemper Amp (nothing else) with 48kHz, record on the USB stick by pushing the button on the u-track,
stop recording by pushing the button on the u-Track and listen to the recording I immediately get the crackling noise.
Switching to 44.1 kHz during recording never shows any Issues. This is 100% reproduceable all times.
Plugging out this u-Track-X32-Card from my x32-Rack-Mixer and plugging it into my x32-Producer never created any Issues no matter what settings I used.
Note:
– If you just use a Microphone it takes around an hour until the crackling noise Shows up
– If you test this with an acoustic guitar (checked out 3 different models) it´s reproduceable after a couple of min.
– It´s completely Independent on any other factors (which channel I use, guitar model, loud, quiet, other settings – no matter what)

So in my eyes this Issue has always been there if you combine u-Track x32 with an x32-Rack Mixer.
I assume it just didn´t show up so far, as many Sound engineers use the x32-Rack as a Stagebox.

I really appreciate, that Lazlo will start to try reproducing this issue in order to find the Problem.

Aside that the u-Track x32 recording card is really relieable with 44.1 kHz on x32-Rack and with no Limits in x32-Producer and I still like it !

If you need any more details on how to reproduce this, I am glad to answer questions as well.

Greetings,
Joe