Hi @Kazuya_WADA,
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.
Please also confirm:
- Is this happening for all endpoints?
- Is this happening for all content (local and streaming)?
- Is the ROCK Core connected to the network any differently than the Mac Mini was?