"For home org connection, use home org connection flow" error occurs when connecting the self org from Data 360 Sandbox

When a Sandbox is created from a production organization where Data 360 is provisioned, and Data 360 is also provisioned in the newly created Sandbox, there will be a [Inactive] connection with the production organization ID displayed by default in the standard connections on the Sandbox side.

To connect the Sandbox's own CRM with Data 360, you only need to activate this [Inactive] connection. The displayed production organization ID will switch to the Sandbox organization ID, completing the connection with your own organization.