When you refresh a sandbox org that’s connected to Salesforce, the org ID changes, but your B2C Commerce instance doesn't recognize the change. As a result, the B2C Commerce features that rely on the Salesforce connection are unavailable. A Disconnect link appears in Business Manager so that you can completely disconnect the affected pairing. You can then reconnect to the same sandbox org or a different one.
Where: This change is available in B2C Commerce.
How: In Business Manager, go to the Salesforce Connection page and click Disconnect. To connect your B2C Commerce instance to a sandbox, click Connections and log in to the sandbox that you want to connect to.