Information
This policy setting controls whether database files (.dbf) opened from an untrusted location are always opened in Protected View.
If you enable this policy setting, database files opened from an untrusted location are always opened in Protected View. Users will not be able to change this setting under File > Options > Trust Center > Trust Center Settings > Protected View.
If you disable or dont configure this policy setting, database files opened from an untrusted location are not opened in Protected View, unless users have changed this setting in the Trust Center.
Note: This policy setting only applies to subscription versions of Office, such as Office 365 ProPlus.
Solution
Policy Path: Microsoft Excel 2016\Excel Options\Security\Trust Center\Protected View
Policy Setting Name: Always open untrusted database files in Protected View