Hi @Juergen_Kijek,
So we can 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 we can have a clear understanding of how your devices are communicating.
When playing to the Sonos devices are they grouped? If you play to them individually do you experience the same behavior? If you play only local content instead of TIDAL does the same behavior occur?