Hi @john john ,
When you restrict your users so that they can only access Sharepoint from company-managed devices, users on unmanaged devices will have browser-only access with no ability to download, print, or sync files. They also won't be able to access content through apps, including the Microsoft Office desktop apps. We cannot define that certain external users (individual users or inside security group) will have full access to the files. Unless you revert back to allow full access.
Reference:https://learn.microsoft.com/en-us/sharepoint/control-access-from-unmanaged-devices
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