A group of Microsoft Products and technologies used for sharing and managing content, knowledge, and applications.
Hi Dave,
The setting option mentioned in your post is used to restrict the access to SharePoint Online and OneDrive data. If you also don't want end users to sync out of office, you can configure the settings mentioned in the article below.
Allow syncing only on computers joined to specific domains
About block the access to SharePoint Online and OneDrive for business data, see the following two articles:
Control access based on network location or app (OneDrive for Business admin center)
Best regards,
Tim