
As this issue is more realted to Microsoft 365 compliance which is not supported on Q&A forum. To better help you, I would suggest you post a new thread with tag "Data Loss Prevention" on following forum.
Microsoft Tech Community
I find one of the Protective actions of DLP policies is "for data at rest, sensitive items can be locked and moved to a secure quarantine location".
According to "DLP policy configuration overview", you may choose what you want to monitor, set a rule that the action to take when the policy conditions are met, such as for On-premises file shares, they would be moved from where it is stored to a quarantine folder".
Please note, the actions depend on the location where the activity is happening.
Then admin can use the Microsoft 365 compliance center to search the unified audit log to view activity in your organization.
If an Answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.