To reproduce:
1. Get a site export from an instance where filesystem attachment storage is configured
2. Import this export into a clustered instance
3. Check the Attachment Storage screen from the admin console. It will display filesystem when you can only store attachments in the database for a cluster. Even though filesystem is displayed, it is still using the database under the hood.

To fix this problem, we will need to ignore the attachment storage setting in global settings imported (for a site import) for clustered instances.