Hello @Gerd_Scholz and welcome. I’ve split out your post to its own support topic; it’s easier for Roon if each problem has its own thread.
In order for Roon’s @support team to better assist you, please provide a brief description of your current setup using this link as a guide.
Make sure to describe your network configuration/topology, including any networking hardware currently in use, so they can have a clear understanding of how your devices are communicating.