You can try the below combinations for the "File Name" customization as per your need.
| Rename Downloaded Files for Deduplication | Rename Downloaded Files with File Name Suffix - Toggle Setting | File Name Suffix - Excluded Object - Populated? | Result |
|---|---|---|---|
| ON | ON | Yes | {FileId}-{filenamesuffix}.{fileextension} |
| ON | OFF | NA | {OriginalFileName}-{FileId}.{fileextension} |
| OFF | ON | Yes | {filenamesuffix}.{fileextension} |
| OFF | OFF | NA | {OriginalFileName}.{fileextension} |
PS: View Mass File Download, Salesforce file download app on Salesforce AppExchange: https://appexchange.salesforce.com/appxListingDetail?listingId=a0N3A00000EcsAOUAZ