EDI file name issue for AS2 integration to partner post migration in webMethods 10.15

I migrated the current webMethods 10.5 version to the webMethods 10.15 version. The partners used AS2 for EDI file transfer from webMethods.

Post-migration, the partner was notified that the EDI file was received as timestamp.dat (2024-04-03112-11-11-623412.dat) instead of timestamp.edi (2024-04-03112-11-11-623412.edi).

I traced the flow and verified the AS2 invocation approach is like SMIME,

and in both environments, the header content approach is the same, like,

application/pkcs7-mime; name=smime.p7m; smime-type=enveloped-data
attachment; filename=smime.p7m

Is there a way to identify the file name? Are there any configurations for sending specific names?

Since the integrations use the partner AS2 URL (host\pub\receive.rsb) to send the requests, are there any rules in the partner system to convert the filename format to specific naming conventions?