USB integration after update AMSv3.1

After the AMSv3.1 uprgrade, which otherwise went fluently, there appears to be a ‘plopping’ sound when starting music. I play over USB from EX (as a player) to DAC. CX is used as server only. This mainly happens at the first start of a session, but not only then.
Also sometimes a following piece of music seems not to play, whereas there should be a signal that I also can see in the choosen player. The DAC also shows no sign of a ‘losing’ usb-signal.
Could this be a software issue? Or should I look elsewhere?

Have you tried reinstalling roonserver and then rebooting both CX & EX?

And have you set each unit up as CX server and EX player by clicking on the functionality button here:

Seems to be a good suggestion. For now everything plays as expected. Installation was allright but reinstalling Roon and rebooting (by pressing front buttons).
I still hear a ‘plopping’ sound but less then before.
I also implemented a resync delay of 500 ms. Perhaps that will also help.