Pi4 4GB with Pro-Ject Pre Box DS2 digital DAC. Random Klicks

Just got my new Pi4 and tried to use it with the USB DAC of my Pro-Ject Pre Box DS2 digital. The DAC is recognized and working, but I got random Clicks and Pops. With the Pi3 it was much worse, but the Pi4 should have better USB Performance? Network is LAN. Different Audio Buffer Size didn’t change anything. Is there another way to getting rid of this Clicks?

Heinz-Juergen

Solved.
Pro-Ject has a Firmware Update on their Website for the Pre Box DS2 digital. Sadly, no Change Log. But it solved the Clicks and Pops.